Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.micromeso.2022.111950

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DOI： 10.1021/acs.inorgchem.2c00128

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DOI： 10.1039/d1cc05893b

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DOI： 10.1246/cl.210525

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DOI： 10.1021/acs.cgd.1c00587

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DOI： 10.1039/d1cc04267j

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DOI： 10.1021/acs.jpcc.1c03351

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Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.1002/asia.202100507

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DOI： 10.1021/jacs.1c02430

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DOI： 10.1246/cl.200785

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry (RSC)  

Understanding the relationship between the geometry of metal-organic frameworks (MOFs) and the CO₂ enthalpy of adsorption is of utmost importance to control CO₂ adsorption/desorption in MOFs and the associated heat...

DOI： 10.1039/d3ta03018k

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Language：English   Publishing type：Research paper (scientific journal)  

This study proposes a CO2 capture process by temperature swing adsorption (TSA) using latent heat of evaporation for liquefied natural gas (LNG) as a cold energy source, which is currently unused and discarded into seawater. The proposed subambient process has several advantages: (1) the total energy cost can be saved by the LNG cold energy; (2) the equilibrium capacity of CO2 at subambient temperature can be increased substantially; and (3) water in the flue gas which would lead to deterioration of the adsorbent can be removed by a pretreatment step utilizing LNG cold energy. For the adsorbent in the TSA system, zeolite 13X, MIL-101, UiO-66, and CPL-1, which are considered effective for CO2 adsorption in the subambient, were considered and adsorption isotherm data were obtained at subambient conditions. Comparisons of these adsorbents were carried out using a rigorous dynamic model of the TSA process. It was found that CPL-1 gives a high recovery rate of 70% and purity of 95%. It was also found that the proposed system has the potential to capture up to 6% of the CO2 emitted from Japan.

DOI： 10.1016/j.ijggc.2023.103910

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Language：English   Publishing type：Research paper (scientific journal)  

Here we report the development of an equimolar conjugate of a metal-organic cage (MOC) and DNA (MOC-DNA). Several MOC-DNA conjugates were assembled into a programmed structure by coordinating with a template DNA having a complementary base sequence. Moreover, conjugation with the MOC drastically enhanced the permeability of DNA through the lipid bilayer, presenting great potential as a drug delivery system.

DOI： 10.1039/d3cc00460k

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PubMed

Publishing type：Research paper (scientific journal)  

DOI： 10.1021/jacs.0c13310

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DOI： 10.1002/smll.202006150

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Molecular motions taking place in the nanospace of metal-organic frameworks (MOFs) are an interesting research subject, although not yet fully investigated. In this work, we utilized in situ Raman spectroscopy in the ultralow-frequency region to investigate the libration motion (including the rotational motion of phenylene rings) of MOFs, in particular [Cu2(bdc)2(dabco)] (Cu-JAST-1), where bdc = 1,4-benzenedicarboxylate and dabco = 1,4-diazabicyclo[2.2.2]octane. The libration mode of Cu-JAST-1 was found to be significantly suppressed by the adsorption of various guest molecules, such as CO2, Ar, and N2. In addition, an appreciable correlation between the libration mode and adsorption equilibrium time was identified, which provides useful novel tools in the design of MOFs acting as molecular adsorption and separation materials.

DOI： 10.1039/d0fd00002g

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Publishing type：Research paper (scientific journal)  

In comparison with the fast development of binary mixture separations, ternary mixture separations are significantly more difficult and have rarely been realized by a single material. Herein, a new strategy of tuning the gate-opening pressure of flexible MOFs is developed to tackle such a challenge. As demonstrated by a flexible framework NTU-65, the gate-opening pressure of ethylene (C H ), acetylene (C H ), and carbon dioxide (CO ) can be regulated by temperature. Therefore, efficient sieving separation of this ternary mixture was realized. Under optimized temperature, NTU-65 adsorbed a large amount of C H and CO through gate-opening and only negligible amount of C H . Breakthrough experiments demonstrated that this material can simultaneously capture C H and CO , yielding polymer-grade (>99.99 %) C H from single breakthrough separation. 2 4 2 2 2 2 2 2 2 4 2 2 2 2 4

DOI： 10.1002/anie.202011802

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PubMed

Publishing type：Research paper (scientific journal)  

Nanoporous materials can adsorb small molecules into their nanospaces. However, the trapping of light gas molecules dissolved in solvents suffers from low concentration and poor adsorption affinity. Here, the reversible trapping and releasing of dissolved oxygen are shown through integrating photosensitization and chemical capturing abilities into a metal–organic framework (MOF), MOMF-1. 9,10-Di(4-pyridyl)anthracene (dpa) ligands in MOMF-1 generates singlet oxygen from triplet oxygen under photoirradiation without additional photosensitizers, and successively reacts with it to produce anthracene endoperoxide, forming MOMF-2, which is proved crystallographically. The reverse reaction also proceeds quantitatively by heating MOMF-2. Moreover, MOMF-1 exhibits excellent water resistance, and completely removes oxygen of ppm order concentrations in water. The new material shown in this report allows controlling of the amount of dissolved oxygen, which can be applicable in various fields relating to numerous oxidation phenomena.

DOI： 10.1002/smll.202004351

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Publishing type：Research paper (scientific journal)  

Framework flexibility is one of the most important characteristics of metal-organic frameworks (MOFs), making them highly suitable for adsorption applications. There have been a limited number of computational efforts to study flexible MOFs in the literature, and they are mostly focused on MIL-53. We studied a flexible MOF known as LMOF-201, which was found to exhibit guest-induced flexible properties; however, the mechanism of the appearance of flexibility is still unclear. First, we validated our simulation results by reproducing the experimental isotherm and powder X-ray diffraction measurements of experimental structures using grand canonical Monte Carlo (GCMC) and reactive force field (ReaxFF) molecular dynamics (MD) simulations. Then, we demonstrated the importance of the presence of a carbonyl oxygen atom in LMOF-201 to induce flexibility. The mechanism determined in this study will enable LMOF-201 to be considered for adsorption applications in the future.

DOI： 10.1039/c9ta12065c

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Publishing type：Research paper (scientific journal)  

Metal organic frameworks (MOFs) are promising porous materials for the adsorption of CO2. Here, we report the study of a luminescent MOF (LMOF), called LMOF-202. We have employed Grand Canonical Monte Carlo (GCMC) simulations to understand and explain the adsorption phenomena inside LMOF-202, and based on the phenomena happening at the molecular level, we have varied the metal ions in LMOF-202 to increase the CO2 affinity and selectivity of the material. We show that the CO2 adsorption capacity and selectivity can be increased by approximately 1.5 times at 1 bar and 298 K by changing the metal ion from Zn to Ba. We also report the feasibility of using this material to capture CO2 from flue gas under realistic conditions (1 bar and 298 K). This work shows that LMOF-202 merits further consideration as a carbon capture adsorbent.

DOI： 10.1021/acsomega.0c01267

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Language：English   Publishing type：Research paper (scientific journal)  

The enhancement of gas adsorption utilizing weak interactions in porous compounds is highly demanding for the design of energy-efficient storage materials. Here, we present a rational design for such an adsorption process by using synergistic functions between dynamic motion in a local module and weak but specific host–guest interactions, that is, halogen-bond (XB) interactions in metal–organic frameworks (MOFs). We designed a new porous coordination polymer (PCP), that is, Br-PCP, the pore surfaces of which are decorated with −CH Br groups and could be useful for interaction with CO molecules. In accordance with our anticipation, in-situ studies suggest that the adsorption step at approximately 54 kPa during CO adsorption is indeed facilitated by XB interactions with little change in the structural volume. This approach of integrating flexible XB modules in rigid PCPs is applicable for designing advanced gas storage systems. 2 2 2

DOI： 10.1002/chem.201904703

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PubMed

Language：English   Publishing type：Research paper (scientific journal)  

The ortho-isomer of molecular hydrogen (o-H ) was converted to the para-isomer (p-H ) within 600 s by using Prussian blue analogs, {M [Cr (CN) ] } (MCr; M = Mn and Ni), as nuclear-spin conversion catalysts. The swift conversion was confirmed by in-situ Raman micro-spectroscopy under an H gas atmosphere (100 kPa) in a low temperature range (2090 K). The o-p ratio observed in MCr deviated from the theoretical value based on the Boltzmann distribution of H in a free rotational state to the para-rich proportion, which suggested the promotion of the o-p conversion at higher temperature. 2 2 3 6 2 2 2 II III

DOI： 10.1246/cl.190829

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Language：English   Publishing type：Research paper (scientific journal)  

Here, we report the adsorptive removal of trace amounts of dimethyl sulfide (DMS) using metal-organic frameworks (MOFs). Cu -based MOFs with open metal sites (OMSs), [Cu (btc) ] (HKUST-1), where btc = 1,3,5-benzenetricarboxylate, and without OMSs, [Cu (bdc) (dabco)] (Cu-JAST-1), where bdc = 1,4-benzenedicarboxylate and dabco = 1,4-diazabicyclo[2.2.2]octane, were investigated for the removal of DMS to compare their performance with that of Ag-Y zeolite, which is currently widely used in industry. HKUST-1 exhibited a considerably higher adsorption capacity for DMS than the other adsorbents, which was confirmed by breakthrough measurements. The adsorption state of DMS with HKUST-1 was directly revealed by single-crystal X-ray diffraction (SXRD) analysis and in situ Raman spectroscopy. In addition, it was shown that DMS can be removed by HKUST-1 even under humid conditions. 2+ 3 2 2 2

DOI： 10.1039/c9ra09702c

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Language：English   Publishing type：Research paper (scientific journal)  

High-quality pure acetylene (C H ) is a kind of crucial starting material for various value-added products. However, selective capture of C H from the main impurity of CO via porous absorbents is a great challenge, as they possess extremely similar kinetic diameters and boiling points, as well as the explosive and reactive properties of C H . Herein, we report a porous coordination polymer (PCP), (NTU-55), which assembled from the coordination between a Cu dimer and a newly designed ligand with a nonmetal selenium (Se) site. Static single-component adsorption and dynamic breakthrough experiments reveal that desolvated NTU-55 can completely adsorb C H from the C H /CO mixture (1/4, v/v) at 298 K, along with higher C H capacity and much lower binding energy. The origin of this separation, as comprehensively revealed by density functional theory (DFT) calculations, is derived from the interaction discriminatory of C H and CO toward accessible Se and Cu adsorption sites. To the best of our knowledge, this is the first time to find the positive effect of nonmetal Se sites for selective C H capture. 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

DOI： 10.1021/acsami.9b20623

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PubMed

Publishing type：Research paper (scientific journal)  

Copyright © 2019 American Chemical Society. Development of proton conduction materials with a high performance via functionalization of porous coordination polymers (PCPs) is challenging yet promising. Herein, a facile and efficient method to synthesize multicarboxylate-group-functionalized rigid ligands has been developed. Interestingly, when utilizing these ligands to prepare PCPs, the peripheral carboxylate groups of the ligands selectively coordinate to the metal ions for constructing the PCP frameworks while ortho-dicarboxylic acid groups on the central benzene ring remain free in the pores. Single-crystal X-ray diffractions and various gas sorption analyses reveal the characteristics of high-density free carboxylic acid groups in the pores of these PCPs, not only forming hydrogen-bond clusters and three-dimensional hydrogen-bond networks potentially, but also stimulating the flexibility of these very robust PCP frameworks. Based on this unique structure, the PCP functionalized with four free carboxylic acids on every ligand (TJU-102) exhibits a high proton conductivity of 5.26 × 10-2 S cm-1 at 90 °C and 98% relative humidity. The activation energy for proton conduction of TJU-102 is ca. 0.59 eV, suggesting that the conduction mechanism is predominantly vehicular.

DOI： 10.1021/acs.chemmater.9b02924

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DOI： 10.1021/jacs.9b07682

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DOI： 10.1039/c9cp04625a

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DOI： 10.1021/jacs.9b07732

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In this study, we report a facile ligand-assisted in situ hydrothermal approach for preparation of compact [Al(OH)(1,4-NDC)] (1,4-NDC=1,4-naphthalenedicarboxylate) MOF membranes on porous γ-Al2 O3 substrates, which also served as the Al3+ source of MOF membranes. Simultaneously, it was observed that the heating mode exerted significant influence on the final microstructure and separation performance of [Al(OH)(1,4-NDC)] membranes. Compared with the conventional hydrothermal method, the employment of microwave heating led to the formation of [Al(OH)(1,4-NDC)] membranes composed of closely packed nanorods with superior H2 /CH4 selectivity.

DOI： 10.1002/asia.201900152

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PubMed

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1039/c8dt04218g

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The ability of porous coordination polymers to undergo reversible structural transformations in response to the presence of guest molecules has been intensively investigated for applications such as molecular separation, storage, sensing and signalling processes. Here we report on the direct observation of the highly guest-responsive nature of the surface of a single-crystalline porous coordination polymer, which consists of paddlewheel zinc clusters and two types of ligand, by in situ liquid-phase atomic force microscopy. Observations were carried out in solution at constant temperature (28 °C) by high-speed atomic force microscopy with lattice resolution. A sharp and reversible response to the presence or absence of biphenyl guest molecules was observed, under conditions that can scarcely induce the transformation of the bulk crystal. Additionally, by modulating the surface coordination equilibrium, layer-by-layer delamination events were captured in real time at every ~13 s per frame.

DOI： 10.1038/s41557-018-0170-0

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PubMed

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1246/cl.180921

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DOI： 10.1021/acs.jpcc.8b08211

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DOI： 10.1038/s41467-018-07889-1

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DOI： 10.1039/c8ce01681j

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DOI： 10.1021/jacs.8b09358

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DOI： 10.1016/j.ica.2018.07.040

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DOI： 10.1126/science.aat6394

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DOI： 10.1039/c8sc02263a

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry  

Kinetic stabilisation of unstable chemical species in nanospace is of potential importance in the field of materials and synthetic chemistry, and porous coordination polymers (PCPs) represent a facile platform to provide such reaction fields. Thiyl radicals are important reactive substances that often play a leading role in organic and bioorganic chemistry. However, their generation in nanospace has been barely investigated due to synthetic difficulties. Here, we report a facile methodology for the functionalisation of active thiyl substituents on PCP pore surfaces using a post-synthetic protection and deprotection technique. The thiyl radicals were generated inside a zinc(ii)-based PCP upon the deprotection of asymmetric disulfides, which were used as the protecting groups by ultraviolet light irradiation.

DOI： 10.1039/c8cc01837e

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley-VCH Verlag  

Separation of gas molecules with similar physical and chemical properties is challenging but nevertheless highly relevant for chemical processing. By introducing the elliptically shaped molecule, 1,4-dimethyl-1,4-diazabicyclo[2.2.2]octane, into the interlayer space of a layered silicate, a two-dimensional microporous network with narrow pore size distribution is generated (MOPS-5). The regular arrangement of the pillar molecules in MOPS-5 was confirmed by the occurrence of a 10 band related to a long-range pseudo-hexagonal superstructure of pillar molecules in the interlayer space. Whereas with MOPS-5 for CO2 adsorption, gate-opening occurs at constant volume by freezing pillar rotation, for CO the interlayer space is expanded at gate-opening and a classical interdigitated layer type of gate-opening is observed. The selective nature of the gate-opening might be used for separation of CO and N2 by pressure swing adsorption.

DOI： 10.1002/anie.201710717

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Here we report a soft porous crystal possessing hemilabile cross-links in its framework that exhibits exclusive gate opening for ethylene, enabling the discriminatory adsorption of ethylene over ethane. A Co-based porous coordination polymer (PCP) bearing vinylogous tetrathiafulvalene (VTTF) ligands, [Co(VTTF)], forms Co-S bonds as intermolecular cross-links in its framework in the evacuated closed state. The PCP recognizes ethylene via d-pi complexation on the accessible metal site that displaces and cleaves the Co-S bond to "unlock" the closed structure. This ethylene-triggered unlocking event facilitates remarkable nonporous-to-porous transformations that open up accessible void space. This structural transformation follows a two-step gate-opening process. Each phase, including the intermediate structure, was successfully characterized by single-crystal X-ray diffraction analysis, which revealed an intriguing "half-open" structure suggestive of a disproportionate gate-opening phenomenon. The gate-opening mechanism was also investigated theoretically; density functional theory and Monte Carlo calculations revealed that the unique "half-open" phase corresponds to a substantially stable intermediate over the possible transformation trajectories. While ethylene opens the gate, ethane does not . because it is unable to coordinate to the Co center. This feature is maintained even at pressures above 1 MPa and at a temperature of 303 K, demonstrating the potential of the "gate-locking/unlocking" mechanism that exploits the hemilabile cross-linking in soft porous crystals.

DOI： 10.1021/jacs.7b10110

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

[Zn-2(FDC)(2)(bpy)] (LMOF-202) and [Zn-2(OFDC)(2)(bpy)] (LMOF-201) (FDC: fluorene-2,7-dicarboxylate, OFDC: 9-fluorenone-2,7-dicarboxylate, bpy: 4,4'-bipyridine) have interpenetrated isostructures. However, their gas sorption behaviors indicate that LMOF-202 is rigid, whereas LMOF-201 is flexible. We found that the structural flexibility of LMOF-201 was due to the addition of only one oxygen atom into the ligand.

DOI： 10.1039/c7dt03338a

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Adsorptions of CO, N-2, NO, and CO2 in a paddle-wheel type porous coordination polymer (PCP) [Cu(aip)] (aip = 5-azidoisophthalate) were investigated with ONIOM[MP4(SDQ):omega B97XD] method using a model system consisting of two [Cu-2(O2CC6H4-R)(4)] units (R = H and Me) and one [Cu-2(O2CC6H4R)(4)] unit, namely, dimer and monomer models. The experimental CO adsorption position was reproduced well by the present calculation with the dimer model. For adsorptions of CO, N-2, NO, and CO2 in the dimer model, the position of gas molecule deviates from the normal one that is found in the monomer model and becomes more distant from the surrounding phenyl group(s) of the neighbor [Cu(aip)] unit. For all of these gas molecules, the calculated binding energy (BE) at the deviating adsorption position is larger than that at the normal one against our expectation that the normal position is the best for the gas adsorption. The deviation of gas adsorption position arises from the interaction between the organic linker (O2CC6H4-R moiety) and gas molecule. For all cases, the exchange repulsion with the organic linker decreases to a larger extent than the attractive electrostatic and dispersion interactions decrease when going from the normal position to the deviating one. To enhance the binding energy of gas molecule, the introduction of electron-donating substituent on phenyl moiety is computationally recommended for this PCP.

DOI： 10.1021/acs.jpcc.7b02707

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

The prevalence of the condensed phase, interpenetration, and fragility of ruesoporous coordination polymers (meso-PCPs) featuring dense open metal sites (OMSs) place strict limitations en their preparation, as revealed by experimental and `theoretical reticular chemistry investigations. Herein, we propose a rational design of stabilized high-porosity meso-PCPs, employing a 'low-symmetry ligand in combination with the shortest linker, formic acid. The resulting dimeric dusters (PCP-31 and PCP-32) exhibit high surface areas, ultrahigh porosities, and high OMS derisities (3.76 and 3.29 nmol g(-1) respectively), enabling highly selective- and effective separation of C2H2 from C2H2/CO2 mixtures at 298 K, as verified by binding energy (BE) and electrostatic potentials (ESP) calculations.

DOI： 10.1021/jacs.7b05702

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：NATURE PUBLISHING GROUP  

Photochromic molecules have shown much promise as molecular components of stimuli-responsive materials, but despite recent achievements in various photoresponsive materials, quantitative conversion in photochemical reactions in solids is hampered by the lack of intrinsic structural flexibility available to release stress and strain upon photochemical events. This issue remains one of the challenges in developing solid-state photoresponsive materials. Here, we report a strategy to realize photoresponsive crystalline materials showing quantitative reversible photochemical reactions upon ultraviolet and visible light irradiation by introducing structural flexibility into crystalline porous frameworks with a twofold interpenetration composed of a diarylethene-based ligand. The structural flexibility of the porous framework enables highly efficient photochemical electrocyclization in a singlecrystal- to-single-crystal manner. CO2 sorption on the porous crystal at 195 K is reversibly modulated by light irradiation, and coincident X-ray powder diffraction/sorption measurements clearly demonstrate the flexible nature of the twofold interpenetrated frameworks.

DOI： 10.1038/s41467-017-00122-5

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1021/jacs.6b11124

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

We present a continuous-wave electron paramagnetic resonance (EPR) study of Cu(ipa) (H2O) (ipa stands for isophthalate ligand) metal organic framework (MOP) that is based on the kagome topology. The main structural unit of this compound is a copper paddle-wheel (PW) consisting of two Cu2+ ions interconnected via four carboxylate groups in the syn- syn fashion. X- and Q-band EPR measurements of this MOF allow us to probe distinct magnetic interactions of different magnitudes that originate from these dinuclear units. EPR experiments performed at different temperatures reveal that two Cu2+ ions in a single PW are antiferromagnetically coupled to the total spin S = 0 state with the exchange coupling constant J = 285 cm(-1). The fine structure pattern observed in the spectra indicates the thermal population of the excited triplet S = 1 spin states of the Cu2+ pairs. Spectral simulations are used to determine the fine and hyperfine structure tensors of the PW units. At higher temperatures a collapse of the fine structure to a single EPR line is observed, indicating the interdinuclear exchange of the S = 1 spin states mediated via the isophthalate linkers. Comparison of the EPR results with the structural X-ray diffraction data reveals that the dehydration of the compound opens an additional spin triplet exchange path joining apical positions of the PWs. We estimated the effective exchange coupling constants in the as-synthesized and dehydrated forms of the compound by simulating the observed powder patterns. It is shown that the additional path is reversibly closed after the dehydrated sample is allowed to interact with air, demonstrating a peculiar relationship between the adsorbed guest molecules and magnetic properties of kagome MOFs even at room temperature.

DOI： 10.1021/acs.jpcc.6b09853

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

The upbuilding of dirhodium tetracarboxylate paddlewheels into porous architectures is still challenging because of the inertness of equatorial carboxylates for ligand-exchange reaction. Here we demonstrate the synthesis of a new family of metal organic cuboctahedra by connecting dirhodium units through 1,3-benzenedicarboxylate and assembling cuboctahedra as porous solids. Carbon monoxide and nitric oxide were strongly trapped in the internal cavity thanks to the strong affinity of unsaturated axial coordination sites of dirhodium centers.

DOI： 10.1021/acs.inorgchem.6b02091

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

An understanding of solid-state crystal dynamics or flexibility in metal-organic frameworks (MOFs) showing multiple structural changes is highly demanding for the design of materials with potential applications in sensing and recognition. However, entangled MOFs showing such flexible behavior pose a great challenge in terms of extracting information on their dynamics because of their poor single-crystallinity. In this article, detailed experimental studies on a twofold entangled MOF (f-MOF-1) are reported, which unveil its structural response toward external stimuli such as temperature, pressure, and guest molecules. The crystallographic study shows multiple structural changes in f-MOF-1, by which the 3D net deforms and slides upon guest removal. Two distinct desolvated phases, that is, f-MOF-1a and f-MOF-1b, could be isolated; the former is a metastable one and transformable to the latter phase upon heating. The two phases show different gated CO2 adsorption profiles. DFT-based calculations provide an insight into the selective and gated adsorption behavior with CO2 of f-MOF-1b. The gate-opening threshold pressure of CO2 adsorption can be tuned strategically by changing the chemical functionality of the linker from ethanylene (-CH2-CH2-) in f-MOF-1 to an azo (-N=N-) functionality in an analogous MOF, f-MOF-2. The modulation of functionality has an indirect influence on the gate-opening pressure owing to the difference in inter-net interaction. The framework of f-MOF-1 is highly responsive toward CO2 gas molecules, and these results are supported by DFT calculations.

DOI： 10.1002/chem.201602087

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

We herein report the divergent and convergent synthesis of coordination star polymers (CSP) by using metal organic polyhedrons (MOPs) as a multifunctional core. For the divergent route, copper-based great rhombicuboctahedral MOPs decorated with dithiobenzoate or trithioester chain transfer groups at the periphery were designed. Subsequent reversible addition fragmentation chain transfer (RAFT) polymerization of monomers mediated by the MOPs gave star polymers, in which 24 polymeric arms were grafted from the MOP core. On the other hand, the convergent route provided identical CSP architectures by simple mixing of a macroligand and copper ions. Isophthalic acid-terminated polymers (so-called macroligands) immediately formed the corresponding CSPs through a coordination reaction with copper(II) ions. This convergent route enabled us to obtain miktoarm CSPs with tunable chain compositions through ligand mixing alone. This powerful method allows instant access to a wide variety of multicomponent star polymers that conventionally have required highly skilled and multistep syntheses. MOP-core CSPs are a new class of star polymer that can offer a design strategy for highly processable porous soft materials by using coordination nanocages as a building component.

DOI： 10.1021/jacs.6b01758

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

The adsorptive separation of C2H2 and CO2 via porous materials is nontrivial due to the close similarities of their boiling points and kinetic diameters. In this work, we describe a new flexible porous coordination polymer (PCP) [Mn(bdc)(dpe)] (H(2)bdc = 1,4-benzenedicarboxylic acid, dpe = 1,2-di(4-pyridyl)ethylene) having zero-dimensional pores, which shows an adsorbate discriminatory gate effect. The compound shows gate opening, type abrupt adsorption for C2H2 but not for CO2, leading to an appreciable selective adsorption of CO2 over C2H2 at near ambient temperature (273 K). The origin of this unique selectivity, as unveiled by in situ adsorption-X-ray diffraction experiments and density functional theory calculations, is due to vastly different orientations between the phenylene ring of bdc and each gas in the nanopores. The structural change by photochemical transformation of this PCP via [2 + 2] photodimerization leads to the removal of inverse CO2/C2H2 selectivity, verifying the mechanism of the guest discriminatory gate effect.

DOI： 10.1021/jacs.5b10491

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Direct observation of gas molecules confined in the nanospace of porous materials by single-crystal X-ray diffraction (SXRD) technique is, significant because it leads to deep insight into the adsorption mechanism and the actual state of the adsorbents in molecular level. A recent study revealed that flexibility is one of the important factors to achieve periodic guest accommodation in the nanospace enabling direct observation of gas molecules. Here, we report a convenient strategy to tune the framework flexibility by just an atomic exchange in a ligand, which enables us to easily construct a soft nanospace as the best platform to study gas adsorption. Indeed, we succeeded to observe C2H2 and CO2 molecules confined in the pores of a flexible porous coordination polymer (PCP-N) in different configurations using SXRD measurement, whereas gas molecules in a rigid framework (PCP-C) isostructural to PCP-N were not seen crystallographically. The result of the coincident in situ powder X-ray diffraction and adsorption measurement for PCP-N unambiguously showed that the framework could flexibly transform to trap gas molecules with a commensurate fashion. In addition, for PCP-N, we found that the adsorbed gas molecules induced significant structural change involving dimensional change of the pore from one-dimensional to three-dimensional, and subsequently, additional gas molecules formed periodic molecular clusters in the nanospace.

DOI： 10.1021/jacs.5b09666

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

The development of highly efficient CO2 separation materials is very important for environmental preservation and energy conservation. Crystalline porous coordination polymers (PCPs)/metal-organic frameworks are one of a number of promising types of porous materials for CO2 separation because of their controllable pore size, shape and surface function. Simultaneously, the unique structural flexibility of PCPs affords both high CO2 selectivity and inexpensive regeneration. However, this family of materials suffers from the coexistence of water that destroys the framework of PCPs and its adsorption in the pores is greater than that of CO2, which results in a deterioration in CO2-separation performance. Herein, a flexible and hydrophobic CuII PCP that is stable towards water has been designed and synthesised. This PCP has extremely high adsorption selectivity for CO2 over CH4, derived from its structural flexibility. Furthermore, the obtained water-tolerant flexible PCP, under CO2/CH4 mixed-gas conditions, exhibits highly selective CO2 adsorption over CH4, even in the presence of water.

DOI： 10.1002/cplu.201500278

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Crystal structure of double-perovskite type BaYMn2O5+delta was studied by high-temperature synchrotron X-ray diffraction (SXRD) under precisely controlled oxygen pressure to gain deeper understanding of the remarkable oxygen intake/release capability of this oxide. The in situ SXRD analysis at 750 degrees C revealed that this oxide undergoes a distinct structural change upon lowering oxygen pressure, from a slightly oxygen-deficient delta = 1 phase (BaYMn2O5.89; P(O-2) = 10(3) Pa) to an oxygen-vacancy ordered delta = 0.5 phase (BaYMn2O5.51; P(O-2) = 10 Pa). The BaYMn2O5.89 structure (orthorhombic Cmmm) involves statistical distribution of oxygen vacancies within the yttrium plane. Meanwhile, the BaYMn2O5.51 structure (orthorhombic Icma) contains arrays of pyramidal MnO5 and octahedral MnO6 forming an alternate ordering, which is stabilized by a particular Mn3+ orbital ordering with collective displacements of Y3+ arrays. Thus, the discontinuous change in the oxygen content can be attributed to the structural reconstruction with oxygen/vacancy redistribution accompanied by yttrium displacement organization.

DOI： 10.1021/jp511648b

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：NATURE PUBLISHING GROUP  

The design of inexpensive and less toxic porous coordination polymers (PCPs) that show selective adsorption or high adsorption capacity is a critical issue in research on applicable porous materials. Although use of Group II magnesium(II) and calcium(II) ions as building blocks could provide cheaper materials and lead to enhanced biocompatibility, examples of magnesium(II) and calcium(II) PCPs are extremely limited compared with commonly used transition metal ones, because neutral bridging ligands have not been available for magnesium(II) and calcium(II) ions. Here we report a rationally designed neutral and charge-polarized bridging ligand as a new partner for magnesium(II) and calcium(II) ions. The three-dimensional magnesium(II) and calcium(II) PCPs synthesized using such a neutral ligand are stable and show selective adsorption and separation of carbon dioxide over methane at ambient temperature. This synthetic approach allows the structural diversification of Group II magnesium(II) and calcium(II) PCPs.

DOI： 10.1038/ncomms6851

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

Highly efficient catalytic isomerization reactions from glucose to fructose in aqueous media using porous coordination polymers (PCPs) or metal-organic frameworks (MOFs) is reported for the first time. The catalytic activity of PCPs functionalized with NH2, (CH3)(2), NO2, and SO3H groups on the pore surface is systematically tested. The catalytic activity can be tuned by the acidity of open metal sites (OMSs) by modifying the organic linkers with the functional groups. As a result, it is demonstrated that MIL-101 functionalized with SO3H not only shows high conversion of glucose but also selectively produces fructose. Further, catalytic one-pot conversion of amylose to fructose is achieved, thanks to the high stability of the framework in an acidic solution. These results show that MOF/PCP compounds having OMSs are promising materials for various useful heterogeneous catalytic reactions, in particular in the biomass field.

DOI： 10.1002/asia.201402119

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

Flexible and dynamic porous coordination polymers (PCPs) with well-defined nanospaces composed of chromophoric organic linkers provide a scaffold for encapsulation of versatile guest molecules through noncovalent interactions. PCPs thus provide a potential platform for molecular recognition. Herein, we report a flexible 3D supramolecular framework {[Zn(ndc)(o-phen)]center dot DMF}(n) (o-phen= 1,10-phenanthroline, ndc=2,6-napthalenedicarboxylate) with confined nanospaces that can accommodate different electron-donating aromatic amine guests with selective turn-on emission signaling. This system serves as a molecular recognition platform through an emission-readout process. Such unprecedented tunable emission with different amines is attributed to its emissive charge-transfer (CT) complexation with o-phen linkers. In certain cases this CT emission is further amplified by energy transfer from the chromophoric linker unit ndc, as evidenced by single-crystal X-ray structural characterization.

DOI： 10.1002/anie.201405619

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

A change of building block from [Ru2(II),(II)(p-FPhCO2)(4)] to [Ru-2(II,II)(4-F-2-OMePhCO2)(4)] in a phenazine hz)-bridged [Ru-2(II,II)] chain compound led to a high selectivity toward nitrogen monoxide (NO) in the adsorption characteristics. High selectivity was observed despite the fact that electronically negative sites that enable close contact with NO molecules are not present in the pores, in contrast to [Ru-2(II,II)(4-Cl-2-OMePhCO2)(4)(phz)], which also exhibited selective NO adsorption.

DOI： 10.1246/cl.140190

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Microporous coordination polymers having various shaped apertures were synthesized and crystallographically characterized using substituted terephthalate ligands. The substituents exert a notable influence on the channel size and shape depending on the orientations and disordering of the phenylene units such as a fin. This is a new aspect of porous coordination polymers, which would provide important information for a precise design of the micropore. (C) 2013 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.micromeso.2013.10.029

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

A porous coordination polymer (PCP) has been synthesized employing an organic ligand in which a stable free radical, isoindoline nitroxide, is incorporated. The crystalline PCP possesses one-dimensional channels decorated with the nitroxyl catalytic sites. When O-2 gas or air was used as the oxidant, this PCP was verified to be an efficient, recyclable, and widely applicable catalyst for selective oxidation of various alcohols to the corresponding aldehydes or ketones.

DOI： 10.1021/ja5019095

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：NATURE PUBLISHING GROUP  

DOI： 10.1038/509434a

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER ASSOC ADVANCEMENT SCIENCE  

Carbon monoxide (CO) produced in many large-scale industrial oxidation processes is difficult to separate from nitrogen (N-2), and afterward, CO is further oxidized to carbon dioxide. Here, we report a soft nanoporous crystalline material that selectively adsorbs CO with adaptable pores, and we present crystallographic evidence that CO molecules can coordinate with copper(II) ions. The unprecedented high selectivity was achieved by the synergetic effect of the local interaction between CO and accessible metal sites and a global transformation of the framework. This transformable crystalline material realized the separation of CO from mixtures with N-2, a gas that is the most competitive to CO. The dynamic and efficient molecular trapping and releasing system is reminiscent of sophisticated biological systems such as heme proteins.

DOI： 10.1126/science.1246423

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PubMed

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Porous coordination polymers (PCPs) have attracted vast interest in recent years because of their possibility for rational design of crystal structures and functional properties. An emerging trend in PCP research is hybridization, which is the subject of this review. We have divided hybrid PCPs into three broad classes: class I, isomorphous mixed metal/ligand PCPs; class II, core@shell PCPs; class III, PCP superset of guest or PCPs with accommodated guests. In this Review, we examine 62 representative hybrid PCPs in the area of gas adsorption/separation/storage, luminescence, catalysis, drug delivery, and ionic conductivity with representative examples of each class to understand the underlying principles of hybridization for PCPs and their advantages over conventional PCPs. The future directions and applications of hybrid PCPs are postulated.

DOI： 10.1021/cm402136z

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

Three new sulfonated porous coordination polymers (PCPs)/metal-organic frameworks (MOFs) have been synthesized using solvothermal methods. These PCPs possess porous structures with non-coordinating sulfonic acid groups or sulfonate with dimethyl ammonium cations and exhibit high proton conductivity at a low humidity of 60% RH (relative humidity) at ambient temperature.

DOI： 10.1039/c3cc47980c

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PubMed

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

A perfluorobutyl-functionalized two-dimensional porous coordination polymer (PCP), {[Cu(bpbtp)(L)(DMF)]center dot(DMF)}(n) (H(2)bpbtp = 2,5-bis(perfluorobutyl) terephthalic acid, L = 2,5-bis(perfluorobutyl)-1,4-bis(4-pyridyl)benzene, DMF = N, N-dimethylformamide) has been synthesized and structurally characterized. The pore surface of the PCP is decorated with pendant perfluorobutyl groups which fabricate a densely fluorinated nanospace resulting in unique gas sorption properties.

DOI： 10.1039/c4cc04505j

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Language：English   Publishing type：Research paper (scientific journal)  

The design of porous materials that undergo selective adsorption of a specific molecule is a critical issue in research on porous coordination polymers or metal-organic frameworks. For the purpose of the selective capture of molecules possessing an electron-acceptor character such as nitric oxide (NO), one-dimensional chain compounds possessing a high donor character have been synthesized using 4-chloroanisate-bridged paddlewheel-type dimetal(II, II) complexes with M = Ru and Rh and phenazine (phz) as the chain linker: [M 2(4-Cl-2-OMePhCO2)4(phz)]·n(CH 2Cl2) (M = Ru, 1
Rh, 2). These compounds are isostructural and are composed of chains with a [-{M2}-phz-] repeating unit and CH2Cl2 occupying the void space between the chains. Compounds 1 and 2 change to a new phase (1-dry and 2-dry) upon evacuating the crystallization solvent (CH2Cl2) and almost lose their pores in the drying process: no void space in 1-dry and 31.8 Å3, corresponding to 2.9% of the cell volume, in 2-dry. Nevertheless, the compounds show a unique gas accommodation ability. Accompanied by a structural transformation (i.e., the first gate-opening) at low pressures of &lt
10 kPa, both compounds show a typical physisorption isotherm for O 2 (90 K) and CO2 (195 K), with the adsorption amount of ca. 2-4 gas molecules per [M2] unit. In addition, the adsorption isotherm for NO (121 K) involves the first gate-opening followed by a second gate-opening anomaly at NO pressures of ≈52 kPa for 1-dry and ≈21 kPa for 2-dry. At the first gate-opening, the absorbed amount of NO is ca. 4 molecules per [M2] unit, and then it reaches 8.4 and 6.3 for 1-dry and 2-dry, respectively, at 95 kPa. Only the isotherm for NO exhibits hysteresis in the desorption process, and some of the NO molecules are trapped in pores even after evacuating at 121 K, although it recovers to the original dried sample on heating to room temperature. The adsorbed NO molecules accrue a significant electron donation from the host framework even in the [Rh2] derivative, indicating that such simple porous compounds with electron-donor characteristics are useful for the selective adsorption of NO. © 2013 American Chemical Society.

DOI： 10.1021/ja4076056

Scopus

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

The chemisorption of sulfur dioxide (SO2) on the Hofmann-like spin crossover porous coordination polymer (SCO-PCP) {Fe(pz)[Pt(CN)(4)]} has been investigated at room temperature. Thermal analysis and adsorption-desorption isotherms showed that ca. 1 mol of SO2 per mol of {Fe(pz)[Pt(CN)(4)]) was retained in the pores. Nevertheless, the SO2 was loosely attached to the walls of the host network and completely released in 24 h at 298 K. Single crystals of {Fe(pz)[Pt(CN)(4)]}center dot nSO(2) (n approximate to 0.25) were grown in water solutions saturated with SO2, and its crystal structure was analyzed at 120 K. The SO2 molecule is coordinated to the Pt-II ion through the sulfur atom ion, Pt-S = 2.585(4) angstrom. This coordination slightly stabilizes the low-spin state of the Fe-II ions shifting the critical temperatures of the spin transition by 8-12 K. DFT calculations have been performed to rationalize these observations.

DOI： 10.1021/ic4020477

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Herein, we report new porous coordination polymers (PCPs) via a facile synthetic approach called "in situ generation of functionality in the ligand". Upon a synthetic process of PCPs, a neutral (-CH2OH) or a cationic functionality (-CH2[4,4'-bipyridine](+)) was generated on a isophthalate ligand from a reactive haloalkane (-CH2Br) moiety, affording two new PCPs. The PCPs have two-dimensional layered structures with large potential solvent-accessible voids for CO2 adsorption.

DOI： 10.1021/ic401924d

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PubMed

J-GLOBAL

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

Gas storage and separation are becoming a high priority area of research due to economic, industrial, and environmental reasons. The last two decades have therefore witnessed dramatic growth in the search for more efficient and adaptable nanoporous materials. In particular, much attention has been focused on porous coordination polymers (PCPs) or metal organic frameworks (MOFs) as new nanoporous materials. Based on the unlimited combination of metal ions and organic ligands, PCPs can provide infinite variety of nanospace in their pores. As molecular adsorption is dependent on the size, shape, and surface nature of nanospace, many unique molecular adsorption or trapping phenomena have been reported in this class of compounds. In this account, I focus on how thoughtful design can lead to the synthesis of porous coordination polymers that demonstrate unprecedented adsorption behavior not found in other porous materials. Examples include selective adsorption of acetylene over carbon dioxide in the CPL series of PCPs, using charge-transfer to induce selective adsorption of nitric oxide and oxygen in TCNQ (7,7,8,8-tetracyano-p-quinodimethane) based PCP and light-induced on-demand adsorption and structural transformations in CID-based PCPs. The guidelines underpinning such unique, highly selective guest adsorption are discussed.

DOI： 10.1246/bcsj.20130157

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PHYSICAL SOC JAPAN  

In a model system of an O-2-O-2 dimer confined in the nanopores of Cu-1,4-cyclohexanedicarboxylic acid, the molecular orientation associated with the spin state was observed by precise synchrotron radiation structure analysis. The obtained charge density level structures revealed that the molecular orientation varied with increasing temperature, coupling with the spin states of the O-2-O-2 dimer. The magnetic properties previously reported were consistently explained by the S = 1 dimer model taking into account the molecular arrangements. The obtained gap parameters are different from those of the O-2-O-2 dimer confined in the nanopores of Cu-2,3-pyrazinedicarboxylate-pyrazine, which is explained by the pore deformation due to the adsorption, depending on the pore size and/or flexibility of the coordination polymer.

DOI： 10.7566/JPSJ.82.084703

Web of Science

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

A porous one-dimensional coordination chain compound, [Ru-2(p-F-PhCO2)(4)(phz)] (1'; p-F-PhCO2- = para-fluorobenzoate; phz = phenazine) derived by drying its nitrobenzene-solvated compound, specifically adsorbs CO2 at 195 K in a stepwise sorption manner.

DOI： 10.1039/c2cc36153a

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

.Starting with the same precursors, pyridine-2,3-dicarboxylate (pyrdc) and 4,4'-bipyridyl (bipy), two 3D porous coordination polymers, ([Cu(bipy)(0.5)(pyrdc)]center dot 3H(2)O} (1) and ([Cu(bipy)(0.5)(pyrdc)].0.5bipy center dot 3H(2)O} (2), have been synthesized by changing the solvent system from MeOH/H2O to EtOH/H2O. Single-crystal structure analysis revealed that 1 and 2 are supramolecular isomers with 3D pillared-layer structures having 1D channel systems. Isomer 1 has a flexible structure and shows gated adsorption behavior, while framework 2 has a rigid backbone and exhibits the adsorption properties of typical microporous materials.

DOI： 10.1021/ic300695v

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Four MIL-101-type porous coordination polymers were synthesized containing different substituents (-H, -NO2, -NH2, -SO3H) in the ligand and their water sorption properties were investigated. All of the compounds adsorbed huge amounts of water (ca. 0.8-1.2 g g(-1)) and the adsorbed water can be released at relatively low temperatures (ca. 353 K). In addition, the trapping pressure of water adsorption was found to be controlled by changing the substituents, varying the hydrophobicity of the functional groups. (C) 2012 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.micromeso.2012.01.015

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

We show that structural changes of a guest molecule can trigger structural transformations of a crystalline host framework. Azobenzene was introduced into a flexible porous coordination polymer (PCP), and cis/trans isomerizations of the guest azobenzene by light or heat successfully induced structural transformations of the host PCP in a reversible fashion. This guest-to-host structural transmission resulted in drastic changes in the gas adsorption property of the host guest composite, displaying a new strategy for creating stimuli-responsive porous materials.

DOI： 10.1021/ja2115713

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

The dynamics of oligo(vinylidene fluoride) (OVDF) confined in regular nanochannels of a porous coordination polymer (PCP) was studied by means of dielectric spectroscopy. The OVDF chains in the PCP nanopores showed two Arrhenius-type relaxation processes at lower temperatures than the relaxation temperature observed for the neat OVDF, showing the enhanced mobility of the confined OVDF.

DOI： 10.1039/c2dt11891b

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

The unique bifunctional porous metal-organic framework, [Co(HLdc)]center dot 1.5MeOH center dot dioxane, incorporates both free-standing carboxyl and pyridyl groups within its pores. Gas adsorption measurements on the desolvated framework reveal unusual selective CO2 adsorption over C2H2 and CH4 linked to a framework phase change from a narrow pore (np) to a large pore (lp) form, mediated by CO2 uptake at 195 K. This phase transition has been monitored by in situ powder X-ray diffraction and IR spectroscopy, and modelled by Grand Canonical Monte Carlo simulations revealing that the reversible np to lp transition is linked to the rotation of pyridyl rings acting as flexible "pore gates".

DOI： 10.1039/c2sc20443f

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

Photochemical [2 + 2] cycloaddition reactions in a two-dimensional interdigitated porous crystalline framework proceed in a single-crystal-to-single-crystal manner, and one-dimensional channels show structural changes that have a significant impact on the CO2 sorption.

DOI： 10.1039/c2cc31083j

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

A simple room temperature reaction of Cu(NO3)(2), and 2,3-pyrazinedicarboxylic acid (H(2)pyzdc) in the presence of dihydroxyfumaric acid (DHFA) resulted in the formation of a highly stable 3D Cu(I) coordination polymer, {[Cu-2(pyzdc)]center dot 0.83H(2)O}(n) where DHFA acts as a reducing agent. It possesses a 1D water filled channel along the crystallographic c direction and the framework shows reversible single-crystal-to-single-crystal structural transformation upon dehydration and rehydration.

DOI： 10.1039/c2ce06701c

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

A detailed investigation into the mechanochemical synthesis of coordination pillared-layer frameworks (CPLs), particularly CPL-1, was carried out. In the case of CPL-1, a two-step reaction was observed (from the starting reactants to the final product). In the conventional solution process, no intermediate state was detected. We found that moisture is essential in both the reaction steps. After the final product was washed, it showed the same sorption ability as the product prepared from a solution process. We further demonstrated the systematic preparation of other CPLs (CPL-2, 3, 4, 5, and 15) by the mechanochemical method under humid conditions, even though some of the ligands are almost insoluble in water. Our findings indicate that mechanochemical synthesis is a promising alternative method for the systematic and large-scale production of PCPs. Its advantages include the following: reduced pollution, low cost, simplicity of the process, ease of handling, efficient reaction rate, selectivity, and the issue of low solubility of reactants is overcome.

DOI： 10.1039/c2dt12012g

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：NATURE PUBLISHING GROUP  

The development of a new methodology for visualizing and detecting gases is imperative for various applications. Here, we report a novel strategy in which gas molecules are detected by signals from a reporter guest that can read out a host structural transformation. A composite between a flexible porous coordination polymer and fluorescent reporter distyrylbenzene ( DSB) selectively adsorbed CO(2) over other atmospheric gases. This adsorption induced a host transformation, which was accompanied by conformational variations of the included DSB. This read-out process resulted in a critical change in DSB fluorescence at a specific threshold pressure. The composite shows different fluorescence responses to CO(2) and acetylene, compounds that have similar physicochemical properties. Our system showed, for the first time, that fluorescent molecules can detect gases without any chemical interaction or energy transfer. The host-guest coupled transformations play a pivotal role in converting the gas adsorption events into detectable output signals.

DOI： 10.1038/NMAT3104

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PubMed

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

A MIL-101-based porous coordination polymer (PCP) containing sulfonic acid groups is synthesized. The sulfonic groups are exposed on the pore surface and act as strong Bronsted acid sites. This solid acid PCP catalytically hydrolyzes cellulose into mono- and disaccharides and shows high durability in the catalytic reaction.

DOI： 10.1002/adma.201101356

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

A new synthetic approach to prepare flexible porous coordination polymers (PCPs) by the use of soft secondary building units (SBUs) which can undergo multiple reversible metal-ligand bonds breaking is reported. We have prepared a zinc paddle-wheel-based two-fold interpenetrated PCP, {[Zn(2)(tp)(2)(L(2))]center dot 2.5DMF center dot 0.5water}(n) (2a, H(2)tp = terephthanlic acid; L(2) = 2,3-difluoro-1,4-bis(4-pyridyl)benzene), showing dynamic structural transformations upon the removal and rebinding of guest molecules. The X-ray structures at different degrees of desolvation indicate the highly flexible nature of the framework. The framework deformations involve slippage of the layers and movement of the two interpenetrated frameworks with respect to each other. Interestingly, the coordination geometry of a zinc paddle-wheel unit (one of the popular SBUs) is considerably changed by bond breaking between zinc and oxygen atoms during the drying process. Two zinc atoms in the dried form 24 reside in a distorted tetrahedral geometry. Compound 24 has no void volume and favors the uptake of O(2) over Ar and N(2) at 77 K The 02 and Ar adsorption isotherms of 24 show gate-opening-type adsorption behaviors corroborating the structure determination. The CO(2) adsorption isotherm at 195 K exhibits multiple steps originating from the flexibility of the framework The structural transformations of the zinc dusters in the framework upon sorption of guest molecules are also characterized by Raman spectroscopy in which the characteristic bands corresponding to v(sym) (COO(-)) vibration were used.

DOI： 10.1021/ja201484s

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

Porous coordination polymers constructed from Zn2+ and isophthalate with linear bipyridyl-type ligands were synthesized. [Zn(ip)(bpb)](n) (CID-21; ip = isophthalate, bpb = 1,4-bis(4-pyridyl)benzene), [Zn(ip)(bpt)](n) (CID-22; bpt= 3,6-bis(4-pyridyl)-1,2,4,5-tetrazine), and [Zn(ip)(bpa)](n) (CID-23; bpa= 1,4-bis(4-pyridyl)acetylene) all have interdigitated structures of layers and similar void volumes (approximate to 27%). In these compounds, 1D bottleneck-type channels run along the perpendicular direction of the layer stacking and their properties are strongly dominated by the dipyridyl linker ligands. Because of the difference in packing of 2D layers, CID-21 and CID-22 have relatively rigid porous structures, whereas CID-23 has greater flexibility, as indicated by the results of powder X-ray diffraction studies. The micropores of CID-22 surrounded by tetrazine moieties adsorb polar molecules, such as methanol and water. The higher affinity of CID-22 for water than CID-21 is supported by a theoretical study. The 1D channel of CID-23 is wider than that of the other two compounds, which enables the incorporation of aromatic molecules. This is because the shape of the bpa linker ligand generates a wider pore diameter (8.6 angstrom). Only CID-23 can adsorb a benzene molecule and the isotherm of benzene has a gate-openingtype profile. This offers proof of the guest accommodation process through large structural transformation from a nonporous to a porous structure. The flexibility and restricted pore space of CID-23, at 298 K, allows only benzene, but not cyclohexane, to enter the channels. The porous structure exhibits clear selectivity for these similar guests. The incorporation of an elongated dipyridyl linker ligand in the 2D coordination layers provides a strategy for the design of microporous compounds with different flexibilities, microporous environments, and separation abilities.

DOI： 10.1002/chem.201003734

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

A series of TCNQ-dianion-based porous coordination polymers [M(TCNQ)bpy] (M = Fe, Zn, Mn, Co, Cd) have been synthesized and characterized. The synthesis reactions of these compounds are promoted by the addition of ascorbic acid, which is the key to obtaining a high yield. They form almost identical three-dimensional pillared layer structures with the M-TCNQ two-dimensional layers linked by bpy pillar ligands. The electronic properties of these compounds vary depending on the constitutional metal ions and guest molecules. We found that the electronic interaction between metal ions and TCNQ moieties in the frameworks strongly impacted the electronic properties of the compounds.

DOI： 10.1021/ic1015498

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

A new 2D pillared-bilayer porous coordination polymer (PCP) has been synthesized and structurally characterized that shows selective adsorption of CO2 over other gases (N-2, O-2, Ar, H-2, CH4) and guest selective single/double-step adsorption of vapor correlated to the successive confinement of adsorbates in a 1D channel and a 2D interlayer space.

DOI： 10.1039/c1cc11416f

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Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Reaction of beta-amino-beta-(pyrid-4-yl)acrylonitrile with the aromatic dicarboxaldehydes 9,10-bis(4formylphenyl)anthracene and terephthalaldehyde affords the dihydropyridyl products 9,10-bis(4-((3,5dicyano-2,6-dipyridyl)dihydropyridyl)phenyl)anthracene (L(1)) and 1,4-bis(4-(3,5-dicyano-2,6-dipyridyl)dihydropyridyl)benzene (L(2)), respectively. In the solid state [L(1)]center dot 2.5DMF center dot 3MeOH (SOF-1) crystallizes in the monoclinic space group P2(1)/C and forms a 3D stable supramolecular organic framework via strong N-H center dot center dot center dot N(py) hydrogen bonds and pi-pi interactions. The material incorporates pyridyl-decorated channels and shows permanent porosity in the solid state. The pore volumes of the desolvated framework SOF-1a calculated from the N(2) isotherm at 125 K and the CO(2) isotherm at 195 K are 0.227 and 0.244 cm(3)g(-1) respectively. The N(2) absorption capacity of SOF-1a at 77 K is very low, with an uptake of 0.63 mmol g(-1) at 1 bar, although saturation N(2) adsorption at 125 K is 6.55 mmol g(-1) (or 143 cm(3) g(-1)). At ambient temperature, SOF-1 a shows significant CO(2) adsorption with approximately 3 mol of CO(2) absorbed per mole of host at 16 bar and 298 K, corresponding to 69 cm(3) g(-1) at STP. SOF-1a also adsorbs significant amounts of C(2)H(2), with an uptake of 124 cm3 (STP) g(-1) (5.52 mmol g(-1)) at 1 bar at 195 K. Methane uptake at 195 K and 1 bar is 69 cm3 (STP) g(-1). Overall, gas adsorption measurements on desolvated framework SOF-1a reveal not only high capacity uptakes for C(2)H(2) and CO(2), compared to other crystalline molecular organic solids, but also an adsorption selectivity in the order C(2)H(2) > CO(2) > CH(4) > N(2). Overall, C(2)H(2)(270 K)/CH(4)(273 K) selectivity is 33.7 based on Henry's Law constant, while the C(2)H(2) (270 K)/CO(2)(273 K) ratio of uptake at 1 bar is 2.05. The less bulky analogue L2 crystallizes in the triclinic space group PT as two different solvates [L(2)]center dot 2DMF center dot 5C(6)H(6) (S2A) and [L(2)]center dot 2DMF center dot 4MeOH (S2B) as pale yellow tablets and blocks, respectively. Each L(2) molecule in S2A participates in two N-H center dot center dot center dot O hydrogen bonds between dihydropyridyl rings and solvent DMF molecules. Packing of these layers generates 1D nanochannels along the crystallographic a and b axes which host DMF and benzene molecules. In S2B, each L(2) ligand participates in hydrogen bonding via an N-H center dot center dot center dot O interaction between the N-H of the dihydropyridyl ring and the O of a MeOH and also via an N-H center dot center dot center dot O interaction between the N center of a pyridine ring and the H-O of a second MeOH molecule. The presence of the L(2)-HO Me hydrogen bonds prevents ligand-ligand hydrogen bonding. As a result, S2B crystallizes as one-dimensional chains rather than as an extended 3D network. Thermal removal of solvents from S2A results in conversion to denser phase S2C which shows no effective permanent porosity.

DOI： 10.1021/ja1042935

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Selective adsorption, so called "molecular sieving", is one of the significant functions of porous materials because it can play an important role in separation processes to obtain highly pure gases or petroleum. One of the next outstanding challenges of porous materials is the achievement of controllable "molecular sieving" in response to external environments. Here, we show a new temperature responsive 1-dimensional porous compound (CPL-11) which changes its structural uniformity in response to ambient temperature, which gives rise to changes in the effective pore size. As a result of the structural responsiveness, the seeming adsorption properties of CPL-11 are apparently opposite to conventional porous compounds expected from thermodynamic law, resulting in a highly selective adsorption for O-2 compared to Ar. This unexpected adsorption behavior indicates that the adsorption properties can be controlled by changing the channel uniformity of a porous framework depending on the ambient temperature.

DOI： 10.1039/c0sc00272k

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

We physisorbed nitric oxide (NO) molecules with spin (S) of 1/2 into the nano-sized pores of the mesoporous medium MCM-41, which allows molecule adsorption of the multi-layer form. The adsorption and desorption isotherms were observed at 121.5 K. and the effects of adsorption efficacy (i.e., the filling ratio, n) on the magnetic properties were investigated. Changes in the condensation state in the temperature region of 100-120 K were observed through the magnetic measurements, and the resultant phase diagram against n resembled that obtained for the physisorption of oxygen (O(2)) molecules with S=1. For T < 90 K, two NO molecules dimerized independently of n and diamagnetic dinitrogen dioxide (N(2)O(2)) was formed. The two-dimensional magnetic state, seen for O(2) physisorption, was not observed in the present system, probably due to the prominent electric polarity of the NO molecule. (C) 2010 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.micromeso.2010.03.028

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：NATURE PUBLISHING GROUP  

Porous compounds are ubiquitous and indispensable in daily life as adsorbents and catalysts. The discovery of a new porous compound with unique properties based on intrinsic nanosized space and surface functionalities is scientifically and technologically important. However, the functional species used in this context are limited to those that are sufficiently inert to not spoil the porous structures. Here, we show a new strategy to achieve a crystalline porous material with the pore surface regularly decorated with highly reactive 'bare' nitrenes that are photonically generated from stable 'dormant' precursors at will. The bare triplet nitrenes were accessible to and reacted with adsorbed oxygen or carbon monoxide molecules, which showed not only activation of the pore surface, but also a high probability of chemical trapping and conversion of guest molecules by light stimulation on demand.

DOI： 10.1038/NMAT2808

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Porous coordination polymers are materials formed from metal ions that are bridged together by organic linkers and that can combine two seemingly contradictory properties-crystallinity and flexibility. Porous coordination polymers can therefore create highly regular yet dynamic nanoporous domains that are particularly promising for sorption applications. Here, we describe the effective selective sorption of dioxygen and nitric oxide by a structurally and electronically dynamic porous coordination polymer built from zinc centres and tetracyanoquinodimethane (TCNQ) as a linker. In contrast to a variety of other gas molecules (C(2)H(2), Ar, CO(2), N(2) and CO), O(2) and NO are accommodated in its pores. This unprecedented preference arises from the concerted effect of the charge-transfer interaction between TCNQ and these guests, and the switchable gate opening and closing of the pores of the framework. This system provides further insight into the efficient recognition of small gas molecules.

DOI： 10.1038/NCHEM.684

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

DOI： 10.1021/cm101410h

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

Three MIL-100-type porous coordination polymers were synthesized using different types of anions and their water sorption properties were investigated. All of the compounds adsorbed huge amounts of water (0.6g g(-1)) at a moderate humidity (P/P-0 < 0.6), and one of the compounds showed the same adsorption property even after two thousand replicate water sorption tests. In addition, the pressure of water adsorption was found to be controlled by counter anions incorporated in the structure, which was attributed to the hydration energy of the anions.

DOI： 10.1246/cl.2010.360

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Adsorption isotherms of N(2), O(2), CO(2), and Xe on a flexible microporous coordination polymer, CPL-2 [Cu(2)(pzdc)(2)(bpy)]center dot(pzdc = pyrazine-2,3-dicarboxylate; bpy = 4,4'-bipyridine), possessing bellows-shaped one-dimensional channels were measured. A nonintegral number of each of the N(2), O(2), CO(2), and Xe molecules can be accommodated in each unit pore, which indicates that all guest molecules are accommoda dated in the so-called "incommensurate fashion". in situ synchrotron X-ray powder diffraction patterns of CPL-2 with guest molecules were recorded. The unit cells were determined from each pattern. It Was found that the host CPL-2 exhibits different crystal transformation with the accommodation of each guest molecule. This indicates that, even in the case of incommensurate adsorption, the flexible framework of a microporous coordination polymer can transform each pore to suit different guest molecules. (C) 2009 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.micromeso.2009.06.023

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Two novel coordination polymers, {[Cu-2(pzdc)(2)L]center dot mH(2)O}n where pzdc is pyrazine-2,3-dicarboxylate and L is 2,7-diazapyrene (CPL-3) and 1,2-azopyridine (CPL-4), respectively, having 3D pillared-layer structure were prepared and the compounds showed gas adsorption properties depending on L.

DOI： 10.1246/cl.2010.218

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Remarkable advances in the recent development of porous coordination polymers (PCPs) or metal organic frameworks (MOFs) have paved the way toward functional chemistry having potential application such as molecular storage, separation, and catalysis. Moreover flexible PCPs, which are structurally transformable depending upon guest molecules adsorption/desorption, have received much attention because they provide unique properties, dissimilar to those of zeolites. PCPs can be categorized into structurally monomodal and multimodal classes. Monomodal PCPs possess single uniform pores in the framework. In contrast, multimodal PCPs have more than two types of pores in the framework. Interpenetrated PCPs can possess more than two types of pores with different sizes and shapes in the same framework depending on relative position of individual motifs, resulting in multimodal PCPs. Moreover, interpenetrated PCPs have several advantages, such as high thermal stability, flexibility, and ultramicropore for effective adsorption. In this review, chemistry of PCPs based on monomodal and multimodal PCPs are summarized and discussed.

DOI： 10.1166/jnn.2010.1494

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In this contribution, we present a coordination framework built from a novel (Zn(4)O)(O(2)C)(6) metaprismatic unit showing the interpenetration of a pair of enantiomorphic lcy nets that exhibits commensurate sorption properties.

DOI： 10.1039/c002924f

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IOP PUBLISHING LTD  

High-field magnetization measurements have been performed at various temperatures on the molecular oxygen adsorbed in a microporous coordination polymer CPL-1. Molecular oxygen with S = 1 forms O(2)-O(2) dimer in the nanochannels of CPL-1. The magnetic properties can be explained by not the S = 1 Heisenberg antiferromagnetic dimer model but the O(2)-O(2) dimer model taking into account the spin-dependent intermolecular potential. This feature is attributed to the fact that the magnetic interaction between O(2) is comparable to the van der Waals force.

DOI： 10.1088/1742-6596/200/2/022018

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The structural flexibility of Cu2+ interdigitated layer type framework was controlled and the compound represented clear separation property of CH4/CO2 at range of 0-1.0 MPa and recovery of adsorbed CO2 above 0.1 MPa.

DOI： 10.1039/c0cc01294g

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

DOI： 10.1002/anie.201002259

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：AMER INST PHYSICS  

In order to visualize molecular interaction by the experimental electrostatic potential analysis we have optimized the optical parameters and developed the high-resolution Debye-Scherrer camera at the RIKEN materials science beamline, BL44B2 of SPring-8. For the purpose the camera was designed to be equipped with the hybrid X-ray detector system. One is the conventional detector, the imaging plate readout off-line to carry out high d (interplanar spacing)-resolution measurements and the other is the CCD detector, which can be operated in a camera at variable distances for high angle-resolution measurements. In addition we have been developing an in-situ properties measurement system to visualize the electrostatic interaction completely synchronized with material functions.

DOI： 10.1063/1.3463354

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Two new 3-fold inter-penetrated 3D microporous metal-organic coordination polymers (MOCPs) of Cu(II), [Cu(3)(blpy)(1.5)(2,6-ndc)(3)](n) (1) and {[Cu(bpe)0.5(2,6-ndc)]center dot 0.5H(2)O}(n) (2) (bipy = 4,4'-bipyridine; bpe 1,2-bis(4-pyridyl)ethane; and 2,6-ndc = 2,6-naphthalenedicarboxylate), have been synthesized using a mixed-ligand system and Structurally characterized by single-crystal X-ray diffraction study. Room-temperature reaction of Cu(II) with bipy and 2,6-ndc affords 1, whereas reaction with bpe and 2,6-ndc yields 2. Structure determination reveals that in both cases, a 2D square grid made by Cu(II) and 2,6-ndc with the aid Of Cu(2)(CO(2))(4) paddlewheel building block is connected by bipy (1) or bpe (2) organic pillar results 3D alpha-polonium type frameworks. Framework I is rigid and robust without any guest molecules, whereas 2 is flexible, realized by the guest induced structural transformations. Both the frameworks show high thermal stability. Framework I and dehydrated form of 2, i.e 2'contains 16.6% and 21.4% void space, respectively and Langmuir surface area calculated from nitrogen adsorption study for 1 and 2' is 113.0 and 337.5 m(2)/g, respectively. Both the frameworks can store approximately 1 wt% of molecular hydrogen at 77 K and 15 bar, in particular, the density of adsorbed hydrogen in 1 is one of the highest reported so far in porous MOCPS. Compounds 1 and 2' can also store 11.0 and 13.2 wt % carbon dioxide at 195 K.

DOI： 10.1021/cm9025683

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The design of pore properties utilizing flexible motifs and functional groups is of importance to obtain porous coordination polymers with desirable functions. We have prepared a 3D pillared-layer coordination polymer, {[Cd(2)(pzdc)(2)L(H(2)O)(2)]center dot 5(H(2)O)center dot(CH(3)CH(2)OH)}(n) (1, H(2)pzdc = 2,3-pyrazinedicarboxylic acid; L = 2,5-bis(2-hydroxyethoxy)-1,4-bis(4-pyridyl)benzene) showing (i) a rotatable pillar bearing ethylene glycol side chains acting as a molecular gate with locking/unlocking interactions triggered by guest inclusion between the side chains, (ii) framework flexibility with slippage of the layers, and (iii) coordinatively unsaturated metal centers as guest accessible sites through the removal of the water coligands. The framework clearly shows reversible single-crystal-to-single-crystal transformations in response to the removal and rebinding of guest molecules, the observation of these processes has provided fundamental clues to the understanding of the sorption profiles. The X-ray structures indicate that the 3D host framework is retained during the transformations, involving mainly rotation of the pillars and slippage of the layers. The structure of dried form 2, [Cd(2)(pzdc)(2)L](n), has no void volume and no water coligands. Interestingly, the adsorption isotherm of water for 2 at 298 K exhibits three distinct steps coinciding with the framework functions. Compound 2 favors the uptake of CO(2) (195 K) over N(2) (77 K) and O(2) (77 K). Above all, we report on a molecular gate with a rotational module exhibiting a locking/unlocking system which accounts for gate-opening type sorption profiles.

DOI： 10.1021/ja904363b

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[Co(NO3)(2)L] (L: 2,6-di(pyrazol-1-yl)pyrazine) (1) exhibits an abrupt transition with hysteresis in magnetic susceptibility between 228 and 240 K. The results of spectroscopic and XRD measurements showed that I is in the high spin state in the whole temperature range. Therefore the observed hysteresis is not due to a spin transition but corresponds to a partial quenching of the angular momentum contribution to the magnetic susceptibility. Crystallographic measurements on the low- and high-temperature form of 1, combined with DFT calculations, showed that a symmetric twisting of the coordinating nitrate ions upon the transition is the most important factor in the orbital quenching mechanism. Utilizing such quenching to control magnetic properties can be a new approach to engineer transition metal complexes with magnetic functionalities without changing their spin or oxidation state.

DOI： 10.1021/ja808448j

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The crystal structure of a microporous coordination polymer with adsorbed methane gas was determined by in situ synchrotron powder diffraction of the gas adsorption and the MEM (maximum entropy method)/Rietveld method. Methane molecules were found to be adsorbed forming a one-dimensional array in the nanochannels of the polymer. The MEM charge density distribution of the adsorbed methane molecules indicated some protrusions which were not observed in that of a spherical atom of adsorbed argon. This was interpreted as a mixed distribution of two uniaxially rotating molecules with different pivotal axes. The methane molecules displayed hindered rotation depending on the shape of the nanopore surface. This result indicates the capability to control the molecular arrangement and orientation by the adsorption of gas molecules on the precisely designed nanopores of coordination polymers.

DOI： 10.1166/jnn.2009.J085

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DOI： 10.1002/anie.200804836

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DOI： 10.1002/chem.200802730

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A new aluminum naphthalenedicarboxylate Al(OH)(1,4-NDC)center dot 2H(2)O compound has been synthesized. The crystal structure exhibits a three-dimensional framework composed of infinite chains of corner-sharing octahedral AI(OH)(2)O(4) with 1,4-naphthanedicarboxylate ligands forming two types of channels with squared-shape cross-section. The large channels present a cross-section of 7.7 x 7.7 angstrom(2), while the. are removed, no structural transformation small channels are about 3.0 x 3.0 angstrom(2) When water molecules occurs, generating a robust structure with permanent porosity and remarkable thermal stability. 2D (1)H-(13)C heteronuclear correlation NMR measurements, together with the application of Lee-Goldburg homonuclear decoupling, were applied, for the first time, to porous coordination polymers revealing the spatial relationships between the (1)H and (13)C spin-active nuclei of the framework. To demonstrate the open pore structure and the easy accessibility of the nanochannels to the gas phase, highly sensitive hyperpolarized (HP) xenon NMR, under extreme xenon dilution, has been applied. Xenon can diffuse selectively into the large nanochannels, while the small ones show no substantial uptake of xenon due to severe restrictions along the channels that prevent the diffusion. Two-dimensional exchange experiments showed the exchange time to be as short as 15 ms. Through variable-temperature HP (129)Xe NMR experiments we were able to achieve an unprecedented description of the large nanochannel space and surface, a physisorption energy of 10 kJ mol(-1), and the chemical shift value of xenon probing the internal surfaces. The large pore channels are straight, parallel, and independent, allowing one-dimensional anisotropic diffusion of gases and vapors. Their walls are composed of the naphthalene moieties that create an unique environment for selective sorption. These results prompted us to measure the storage capacity toward methanol, acetone, benzene, and carbon dioxide. The selective adsorption of methanol and acetone vs that of water, together with the permanent porosity and high thermal stability, makes this compound a suitable matrix for separation and purification.

DOI： 10.1021/ja802589u

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The magnetic and photo-magnetic properties of Co dinuclear compounds were studied. The Co compounds, [{Co(tpa)}(2)(dhbq)](BF(4))(3) center dot 2H(2)O and [{Co(tpa)}(2)(dhbq)](ClO(4))(3) center dot 2H(2)O, have the structure [(tpa)Co(III-LS)-(mu-dhbq)(3) -Co(III-LS)(tpa)](3) (where LS, H(2)dhbq, tpa denote low-spin, 2,5-di-hydroxy-1,4-benzoquinone and tris(2-pyridylmethyl)amine, respectively) at room temperature. On heating, these compounds exhibit valence-tautomeric inter-conversion; [(tpa)Co(III-LS) -(mu-dhbq)(3) -Co(III-LS)(tpa)](3) reversible arrow [(tpa)Co(II-HS)-(mu-dhbq)(2) -Co(III-LS)(tpa)](3) (where HS denotes high-spin). Furthermore, both of these compounds exhibit photo-induced valence tautomerism at low temperature (< 60 K). These results show that the electronic structures of these complexes can be controlled by modifying the counter anions. (c) 2008 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.ica.2008.03.089

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The acetylene-sorption properties of six porous coordination polymers (PCPs), [M-2(L)(2)(dabco)](n) (dabco = 1,4-diazabicyclo[2.2.2]octane, M = Cu2+ (1), Zn2+ (2), L = 1,4-benzenedicarboxylate (bdc; 1a, 2a), 1,4-naphthalenedicarboxylate (ndc; 1b, 2b), 9,10-anthracenedicarboxylate (adc; 1c, 2c)), were investigated. The acetylene sorption isotherms of 1 and 2 measured at 195 K are of type I and show a steep increase at low relative pressures. The sorption properties of carbon dioxide at 195 K were also investigated. Compounds 1 and 2 showed a large difference in onset pressure between acetylene sorption isotherms, although the difference between the carbon dioxide sorption isotherms is not so significant. In particular, 2c displayed a remarkable affinity for acetylene. The acetylene sorption isotherm at 298 K showed that the adsorption amounts for 2c and 2b at 298 K, 1 atm (101 and 106 mL g(-1), respectively) were higher than those of other conventional porous materials. Notably, of the compounds 1 and 2, the porous crystals 2c had the highest affinity for acetylene.

DOI： 10.1002/asia.200800112

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Recently, syntheses of epoch-making space materials using coordination compounds are underway by various groups. The rational synthetic strategy of the space of coordination compounds provides unique structures and functions, which have not been found in traditional materials. Now, we intend to focus on this scientific field from a new viewpoint. We define coordination space as the space where the coordination bond plays an important role in the formation of the spatial structures and where various physical properties are exhibited. In this article, we focus on the coordination spaces provided by porous coordination polymers, and their uniqueness is illustrated with current representative results. (C) 2007 Elsevier B. V. All rights reserved.

DOI： 10.1016/j.ccr.2007.07.009

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We have designed and synthesized a flexible porous coordination polymer with highly selective capacity to separate benzene from cyclohexane. The undulating channel providing the suitable space for the benzene and the H-pi interaction between the host framework and the guest molecules result in this high selectivity.

DOI： 10.1021/ja073505z

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A number of photofunctional molecular compounds have been developed recently. Typical examples of these are phototunable valence tautomeric compounds, which are now attracting great attention. When the charge-transfer bands of some Co valence tautomeric compounds are excited at low temperature, metastable redox isomers can be created after irradiation. The lifetimes of the metastable states can be more than several hours. These transformations can involve changes in the magnetic properties of the compounds, as well as their color. Hence, these compounds can be regarded as novel photomagnetic materials. The photoresponsive behaviors of these valence tautomeric compounds are similar to those of spin-crossover complexes (light-induced excited spin-state trapping effects).

DOI： 10.1021/ar600014m

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To create a functionalized porous compound, amide group is used in porous framework to produce attractive interactions with guest molecules. To avoid hydrogen-bond formation between these amide groups our strategy was to build a three-dimensional (3D) coordination network using a tridentate amide ligand as the three-connector part. From Cd(NO3)(2)center dot 4H(2)O and a three-connector ligand with amide groups a 3D porous coordination polymer (PCP) based on octahedral Cd(II) centers, {[Cd(4-btapa)(2)(NO3)(2)]center dot 6H(2)O center dot 2DMF}(n) (1a), was obtained (4-btapa = 1,3,5-benzene tricarboxylic acid tris[N-(4-pyridyl)amide]). The amide groups, which act as guest interaction sites, occur on the surfaces of channels with dimensions of 4.7 x 7.3 A(2). X-ray powder diffraction measurements showed that the desolvated compound (1b) selectively includes guests with a concurrent flexible structural (amorphous-to-crystalline) transformation. The highly ordered amide groups in the channels play an important role in the interaction with the guest molecules, which was confirmed by thermogravimetric analysis, adsorption/desorption measurements, and X-ray crystallography. We also performed a Knoevenagel condensation reaction catalyzed by 1a to demonstrate its selective heterogeneous base catalytic properties, which depend on the sizes of the reactants. The solid catalyst 1a maintains its crystalline framework after the reaction and is easily recycled.

DOI： 10.1021/ja067374y

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Introducing a functional part into open-framework materials that tunes the pore size/shape and overall porous activity will open new routes in framework engineering and in the fabrication of new materials. We have designed and synthesized a bimodal microporous twofold interpenetrating network {[Ni(bpe)(2)(N(CN)(2))](N(CN)(2))(5H2O)}(n) (1), with two types of channel for anionic N(CN)(2)(-) (dicyanamide) and neutral water molecules, respectively. The dehydrated framework provides a dual function of specific anion exchange of free N(CN)(2)(-) for the smaller N-3(-) anions and selective gas sorption. The N-3-exchanged framework leads to a dislocation of the mutual positions of the two interpenetrating frameworks, resulting in an increase in the effective pore size in one of the counterparts of the channels and a higher accommodation of adsorbate than in the as-synthesized framework (1), showing the first case of controlled sorption properties in flexible porous frameworks.

DOI： 10.1038/nmat1827

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This paper reports a novel crystal growth system of a coordination framework {[Cu-3(CN)(3){hat(CN)(3)(OEt)(3)}]}n (1) (hat-(CN)(3)(OEt)(3)) 2,6,10-tricyano-3,7,11-triethoxy-1,4,5,8,9,12-hexaazatriphenylene). The coordination polymer is crystallized through the reaction of 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12hexaazatriphenylene (hat-(CN)(6)), ethanol, and copper(I) complex, involving the breaking and forming of covalent bonds. The crystal morphologies obtained in the present system contain dumbbells, cogwheels, and superlattices. Moreover, in the growth perpendicular to the c-axis, periodic ramification at regular interval is observed, affording superlattice morphologies. Observation of the growth of dumbbell crystals shows that the growth rates parallel and perpendicular to the crystallographic c-axis are quite different: the former shows a drastic change with the reaction duration, while the latter is almost constant. These results are reproduced as a simple reaction-diffusion system, indicating that chemical reactions on crystal surfaces play an important role in determining the macroscopic crystal morphologies.

DOI： 10.1021/ja065254k

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DOI： 10.1021/ja0660047

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A porous coordination polymer (PCP) with immobilization of sodium cations on the pore surface has been synthesized, by employing a bifunctional carboxylate/sulfonate ligand, and structurally characterized. The porous framework with 1D channels of the dimension of 4.9 × 4.9 ?2 shows high thermal stability (?330 °C), affording Type I adsorption isotherms for CO2, acetone, and benzene. The chemical shift of 13C NMR and characteristic adsorption energy (βE0) of acetone adsorbed in this compound represent the Lewis acidity of this framework. Copyright ? 2006 American Chemical Society.

DOI： 10.1021/ja0606879

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DOI： 10.1002/anie.200600976

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DOI： 10.1002/anie.200603196

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Molecules and atoms confined in a nanospace may have properties distinctly different from those of the bulk fluid, owing to the formation of a specific molecular array characteristic of nanospace. In situ synchrotron powder X-ray diffraction measurements have been used to observe confined guest molecules such as N(2), O(2), Ar, and CH(4) in the well-regulated ultramicropore of a copper coordination polymer, 1 ([Cu(2),(pzdc)(2)pyz]: pzdc = 2,3-pyrazinedicarboxylate and pyz = pyrazine). The obtained crystal structures indicate that guest molecules are confined in a linear fashion to form crystal ine-like regular ordered arrays, in contrast to the situation in the gas and liquid state, even at temperatures above the boiling point, and the ordered arrays are characteristic of the kind of gas molecule and the geometrical and potential properties of the ultramicropore of 1.

DOI： 10.1021/jp054411j

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

A metal-organic honeycomb-like 2D pillared-bilayer open framework has been constructed which shows dynamic sponge-like single-crystal-to-single-crystal transformation upon dehydration and rehydration. The dehydrated acentric nonporous phase transformed to the porous centric phase with the selective adsorbate concomitant with the structural transformation correlated with the single-crystal structure determination. Copyright ? 2005 American Chemical Society.

DOI： 10.1021/ja0561439

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ACADEMIC PRESS INC ELSEVIER SCIENCE  

In a decade, many porous coordination polymers have been synthesized, providing a variety of properties ranging from storage, separation and exchange of guests in their cavities, magnetism, conductivity and catalysis by their frameworks. Recent advent of flexible porous coordination polymers, which exhibit elastic guest accommodation in contrast to rigid three-dimensional (3-D) frameworks of conventional porous materials, have acquired a position as a new class of porous materials. Such flexible porous properties induce highly selective guest accommodation and magnetic modulation, which could now be a unique class of practical materials. In this review, we introduce recent flexible porous coordination polymers (3-17) and their functional properties, categorizing with the four types of pores with framework deformation. (c) 2005 Published by Elsevier Inc.

DOI： 10.1016/j.jssc.2005.05.036

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：NATURE PUBLISHING GROUP  

Metal - organic microporous materials(1-4) (MOMs) have attracted wide scientific attention owing to their unusual structure and properties, as well as commercial interest due to their potential applications in storage(5-9), separation(10,11) and heterogeneous catalysis(12,13). One of the advantages of MOMs compared to other microporous materials, such as activated carbons, is their ability to exhibit a variety of pore surface properties such as hydrophilicity and chirality, as a result of the controlled incorporation of organic functional groups into the pore walls(11,13-15). This capability means that the pore surfaces of MOMs could be designed to adsorb specific molecules; but few design strategies for the adsorption of small molecules have been established so far. Here we report high levels of selective sorption of acetylene molecules as compared to a very similar molecule, carbon dioxide, onto the functionalized surface of a MOM. The acetylene molecules are held at a periodic distance from one another by hydrogen bonding between two non-coordinated oxygen atoms in the nanoscale pore wall of the MOM and the two hydrogen atoms of the acetylene molecule. This permits the stable storage of acetylene at a density 200 times the safe compression limit of free acetylene at room temperature.

DOI： 10.1038/nature03852

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In this manuscript, we report synthesis and crystal structure of a novel coordination polymer of Cd(II), {[Cd(pzdc)(bpp)(H2O)]3 2O}n (3) and porous functionalities of {[Cd(pzdc)(azpy)]2H2O}n (1), {[Cd(pzdc)(bpee)]1.5H2O}n(2) and 3 [where pzdc = pyrazine-2,3-dicarboxylate, azpy = 4,4' -azopyridine; bpee = 1,2-bis-(4-pyridyl)ethylene and bpp =1,3-bis(4-pyridyl)propane]. Structure determination reveals that complex 3 is a 3D porous framework with one dimensional micro-channel along the crystallographic c-axis (channel size: 8.4*4.2 ?; Vvoid = 17.2%), where each Cd(II) is in distorted octahedral environment and attached with two pzdc, two bpp ligand and one water molecule. The TGA analysis shows that the dehydrated framework is stable up to 180°C and XRPD measurement suggests that the dehydrated materials become amorphous, but with exposure to the water vapor regenerates the original framework. Adsorption measurement shows that water molecules are adsorbed in two-step process, whereas MeOH molecules in a single step and both the sorption phenomena occur with large hysteresis. ? 2005 Elsevier B.V. All rights reserved.

Language：English   Publishing type：Research paper (scientific journal)  

Molecular motions of methanol and aromatic molecules (benzene, toluene, p-xylene) adsorbed in 1D nanochannels of pillared-layer coordination polymers with paramagnetic metal ions have been studied by2H NMR together with X-ray crystallography. NMR spectra at various temperatures and Rietveld analyses of powder X-ray diffractions represented that the characteristic shape and periodic potential of each micropore confined guests in highly restricted motions and ordering even though the guests are physisorbed. ? 2005 Elsevier B.V. All rights reserved.

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

Trapped hydrogen molecules in the nanochannels of a copper coordination polymer were successfully observed by the synchrotron powder-diffraction method. The adsorbed molecules are located near one corner of the rectangular nanochannels, and the pockets of the pore walls are suited to the size of the hydrogen molecules (see picture). These results could provide guidelines for the design of hydrogen-storage materials.

DOI： 10.1002/anie.200461895

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PROGRESS THEORETICAL PHYSICS PUBLICATION OFFICE  

The magnetic properties of O-2 adsorbed in nanochannels of porous metal-organic solids CPL-1 and CPL-p1 have been investigated by means of high-field magnetization process measurement. The contribution from adsorbed 02 shows the metamagnetic-like behavior in both compounds. We propose "the field-induced rearrangement mechanism" as the explanation for the metamagnetic-like behavior. It is known for the O-2-O-2 dimer that the magnetic interaction depends strongly on the intermolecular distance and the orientation of molecular axes. It is considered naturally that the stable arrangement with saturated magnetic moment in the sufficient high field is different from the H-structure which is stable at zero field.

DOI： 10.1143/PTPS.159.271

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Language：English   Publishing type：Research paper (scientific journal)  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Molecular motions of methanol and aromatic molecules (benzene, toluene, p-xylene) adsorbed in ID nanochannels of pillared-layer coordination polymers with paramagnetic metal ions have been studied by H-2 NMR together with X-ray crystallography. NMR spectra at various temperatures and Rietveld analyses of powder X-ray diffractions represented that the characteristic shape and periodic potential of each micropore confined guests in highly restricted motions and ordering even though the guests are physisorbed.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

In this manuscript, we report synthesis and crystal structure of a novel coordination polymer of Cd(II), {[Cd(pzdc)(bpp)(H2O)](3)H2O}(n) (3) and porous functionalities of ([Cd(pzdc)(azpy)[2H(2)O}(n). (1), {[Cd(pzdc)(bpee)]1.5H(2)O}(n) (2) and 3 [where pzdc pyrazine-2,3-dicarboxylate, azpy = 4,4'-azopyridine; bpee = 1,2-bis-(4-pyridyl)ethylene and bpp = 1,3-bis(4-pyridyl)propane]. Structure determination reveals that complex 3 is a 3D porous framework with one dimensional micro-channel along the crystallographic c-axis (channel size: 8.4 x 4.2 angstrom; V-void = 17.2%), where each Cd(II) is in distorted octahedral environment and attached with two pzdc, two bpp ligand and one water molecule. The TGA analysis shows that the dehydrated framework is stable up to 180 degrees C and XRPD measurement suggests that the dehydrated materials become amorphous, but with exposure to the water vapor regenerates the original framework. Adsorption measurement shows that water molecules are adsorbed in two-step process, whereas MeOH molecules in a single step and both the sorption phenomena occur with large hysteresis.

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Language：English   Publishing type：Research paper (scientific journal)  

Molecular motions of methanol adsorbed in 1D nano-channels of pillared-layer coordination polymer with paramagnetic metal ions have been studied by 2H NMR together with X-ray crystallography.

Language：English   Publishing type：Research paper (scientific journal)  

measured (pzdc = pyrazine-2,3-dicarboxylate, bpy = 4,4′-bipyridine) (where G = H2O for CPL-2 ⊃ H2O, G = benzene for CPL-2 ⊃ benzene, and G = void for the apohost). The structures of apohost and CPL-2 ⊃ benzene were determined from Rietveld analysis. Adsorption of benzene in the channels induced a remarkable contraction in the crystal (b axis; 6.8%, volume; 4.9%), although the channels were occupied by the benzene molecules. This crystal transformation provides a new pore structure that is well suited for benzene molecules, and we denote it as a "shape-responsive fitting" transformation. This type of pore gives rise to a new guideline: frameworks can be composed of flexible motifs that are linked via strong bond and/or stiff motifs that are connected via weaker bonds.

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

In situ synchrotron X-ray powder diffraction patterns of porous coordination polymers {[Cu-2-(pzdc)(2)(bpy)](.)G} have been measured (pzdc = pyrazine-2,3-dicarboxylate, bpy = 4,4'-bipyridine) (where G = H2O for CPL-2 superset of H2O, G = benzene for CPL-2 superset of benzene, and G = void for the apohost). The structures of apohost and CPL-2 superset of benzene were determined from Rietveld analysis. Adsorption of benzene in the channels induced a remarkable contraction in the crystal (b axis; 6.8%, volume; 4.9%), although the channels were occupied by the benzene molecules. This crystal transformation provides a new pore structure that is well suited for benzene molecules, and we denote it as a "shape-responsive fitting" transformation. This type of pore gives rise to a new guideline: frameworks can be composed of flexible motifs that are linked via strong bond and/or stiff motifs that are connected via weaker bonds.

DOI： 10.1021/ja046925m

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A new three-dimensional (3-D) jungle-gym-like open metal-organic framework has been synthesized from a two-dimensional (2-D) layer compound using a heterogeneous pillar insertion reaction. Both the starting 2-D layer and the resulting 3-D open compounds have been characterized using X-ray crystallography.

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

A new three-dimensional (3-D) jungle-gym-like open metal-organic framework has been synthesized from a two-dimensional (2-D) layer compound using a heterogeneous pillar insertion reaction. Both the starting 2-D layer and the resulting 3-D open compounds have been characterized using X-ray crystallography.

DOI： 10.1021/ic049005d

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Rationally designed and synthesized, two novel pillar-layered 3D microporous frameworks {[Cd(pzdc)(azpy)]?2H2O}n, (1, left) and {[Cd(pzdc)(bpee)]?1.5H2O}n, (2, right) have high thermal stability and highly selective adsorption properties. Removal of guest water molecules results in the expansion of 1 but the contraction of 2.

Language：English   Publishing type：Research paper (scientific journal)  

Wall decoration: Coordinatively unsaturated metal centers (CuII, CoII, and NiII) can be embedded in the pore wall of a microporous coordination polymer containing Schiff base type metalloligands [M(salphdc)]2- (H4salphdc = N,N' -o- phenylenebis(salicylideneimine-5,5' -dicarboxylic acid)). These coordination polymers possess large 1D channels with dimensions of approximately 14 * 14 ?2 (see structure).

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The magnetic properties of molecular oxygen adsorbed in the micro-porous metal-organic solids have been investigated. Adsorbed O2 molecules form a ladder structure in the nanochannels of CPL-1. The temperature dependence of susceptibility and the high-field magnetization process indicate the nonmagnetic ground state of the adsorbed O2 at low temperatures. ? 2003 Elsevier B.V. All rights reserved.

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

The magnetic properties of molecular oxygen adsorbed in the micro-porous metal-organic solids have been investigated. Adsorbed O-2 molecules form a ladder structure in the nanochannels of CPL-1. The temperature dependence of susceptibility and the high-field magnetization process indicate the nonmagnetic ground state of the adsorbed O-2 at low temperatures. (C) 2003 Elsevier B. V. All rights reserved.

DOI： 10.1016/j.jmmm.2003.11.327

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

Rationally designed and synthesized, two novel pillar-layered 3D microporous frameworks {[Cd(pzdc)(azpy)]?2H2O}n, (1, left) and {[Cd(pzdc)(bpee)]?1.5H2O}n, (2, right) have high thermal stability and highly selective adsorption properties. Removal of guest water molecules results in the expansion of 1 but the contraction of 2.

DOI： 10.1002/anie.200453923

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

Molecular motions of methanol adsorbed in 1D nanochannels of pillared-layer coordination polymer with paramagnetic metal ions have been studied by H-2 NMR together with X-ray crystallography.

DOI： 10.1039/b406883a

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

Wall decoration: Coordinatively unsaturated metal centers (CuII, CoII, and NiII) can be embedded in the pore wall of a microporous coordination polymer containing Schiff base type metalloligands [M(salphdc)]2- (H4salphdc = N,N′-o- phenylenebis(salicylideneimine-5,5′-dicarboxylic acid)). These coordination polymers possess large 1D channels with dimensions of approximately 14 × 14 ?2 (see structure).

DOI： 10.1002/anie.200352596

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Language：English  

© Springer Nature Singapore Pte Ltd. 2019. Metal-organic frameworks (MOFs) have received continuous attention because of their highly porous, diversified structures and potential applications as novel adsorbents. In this chapter, the recent progress in developing MOFs for CO 2 capture is reviewed. Several strategies being used to improve CO 2 adsorption uptake at low pressure are highlighted. These strategies are generation of interaction sites in the pores as well as controlling of pore size of MOFs, building of flexible MOFs, and construction of water-stable MOFs. In addition, the high-pressure CO 2 adsorption in highly porous MOFs is reviewed. At last, the studies of CO 2 -loaded structures with crystallographic technique are summarized.

DOI： 10.1007/978-981-13-3504-4_12

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© 2019 American Chemical Society. Development of proton conduction materials with a high performance via functionalization of porous coordination polymers (PCPs) is challenging yet promising. Herein, a facile and efficient method to synthesize multicarboxylate-group-functionalized rigid ligands has been developed. Interestingly, when utilizing these ligands to prepare PCPs, the peripheral carboxylate groups of the ligands selectively coordinate to the metal ions for constructing the PCP frameworks while ortho-dicarboxylic acid groups on the central benzene ring remain free in the pores. Single-crystal X-ray diffractions and various gas sorption analyses reveal the characteristics of high-density free carboxylic acid groups in the pores of these PCPs, not only forming hydrogen-bond clusters and three-dimensional hydrogen-bond networks potentially, but also stimulating the flexibility of these very robust PCP frameworks. Based on this unique structure, the PCP functionalized with four free carboxylic acids on every ligand (TJU-102) exhibits a high proton conductivity of 5.26 × 10-2 S cm-1 at 90 °C and 98% relative humidity. The activation energy for proton conduction of TJU-102 is ca. 0.59 eV, suggesting that the conduction mechanism is predominantly vehicular.

DOI： 10.1021/acs.chemmater.9b02924

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DOI： 10.4019/bjscc.57.45

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Coordination Polymers (CPs) are opening up a new field in porous materials. A large number of CPs have been so far synthesized and characterized because of their versatile applicability to gas storage, molecular sieves, size- or shape-selective catalysis, and ion exchange. Moreover, CPs, in spite of their crystalline form, are suitable for creating flexible and dynamic porous frameworks, which are hardly realized by inorganic zeolites and carbon materials. We described here the several unique structures and functions of CPs.

DOI： 10.5940/jcrsj.46.53

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