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DOI： 10.1002/anie.202306853

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Nuclear magnetic resonance (NMR) spectroscopy is one of the indispensable techniques in chemistry because it enables us to obtain accurate information on the chemical, electronic, and dynamic properties of molecules. Computational simulation of the NMR spectra requires time-consuming density functional theory (DFT) calculations for an ensemble of molecular conformations. For large flexible molecules, it is considered too high-cost since it requires time-averaging of the instantaneous chemical shifts of each nuclear spin across the conformational space of molecules for NMR timescales. Here, we present a Gaussian process/deep kernel learning-based machine learning (ML) method for enabling us to predict, average in time, and analyze the instantaneous chemical shifts of conformations in the molecular dynamics trajectory. We demonstrate the use of the method by computing the averaged 1H and 13C chemical shifts of each nuclear spin of a trefoil knot molecule consisting of 24 para-connected benzene rings (240 atoms). By training ML model with the chemical shift data obtained from DFT calculations, we predicted chemical shifts for each conformation during dynamics. We were able to observe the merging of the time-averaged chemical shifts of each nuclear spin in a singlet 1H NMR peak and two 13C NMR peaks for the knot molecule, in agreement with experimental measurements. The unique feature of the presented method is the use of the learned low-dimensional deep kernel representation of local spin environments for comparing and analyzing the local chemical environment histories of spins during dynamics. It allowed us to identify two groups of protons in the knot molecule, which implies that the observed singlet 1H NMR peak could be composed of the contributions from protons with two distinct local chemical environments.

DOI： 10.1063/5.0147398

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DOI： 10.1007/s00214-023-02982-1

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DOI： 10.1002/anie.202301962

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DOI： 10.1002/anie.202218297

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A novel Ag-based coordination polymer with a bright phosphorescence originating from metal–metal to ligand charge transfer was synthesized. The Ag⋯Ag-related emission path and structural rigidity resulted in outstanding luminescence efficiency.

DOI： 10.1039/d3cc00179b

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DOI： 10.1002/anie.202301460

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DOI： 10.1021/acs.inorgchem.2c03681

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DOI： 10.1142/s1088424623500189

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DOI： 10.1142/s1088424622500754

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Critical chain length that divides small molecular crystallization from macromolecular crystallization is an important index in macro-organic chemistry to predict chain-length dependent properties of oligomers and polymers. However, extensive researches...

DOI： 10.1039/d2sc03083g

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DOI： 10.1021/acs.jpcc.2c01979

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Abstract

Technologies for the creation of topological carbon nanostructures have greatly advanced synthetic organic chemistry and materials science. Although simple molecular nanocarbons with a belt topology have been constructed, analogous carbon nanobelts with a twist—more specifically, Möbius carbon nanobelts (MCNBs)—have not yet been synthesized owing to their high intrinsic strain. Here we report the synthesis, isolation and characterization of a MCNB. Calculations of strain energies suggest that large MCNBs are synthetically accessible. Designing a macrocyclic precursor with an odd number of repeat units led to a successful synthetic route via Z-selective Wittig reactions and nickel-mediated intramolecular homocoupling reactions, which yielded (25,25)MCNB over 14 steps. NMR spectroscopy and theoretical calculations reveal that the twist moiety of the Möbius band moves quickly around the MCNB molecule in solution. The topological chirality that originates from the Möbius structure was confirmed experimentally using chiral HPLC separation and circular dichroism spectroscopy.

DOI： 10.1038/s44160-022-00075-8

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society ({ACS})  

DOI： 10.1021/jacsau.1c00516

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DOI： 10.1002/chem.202200056

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Cyclic polyketones composed of acetylacetone analogues showed crown ether-like alkali metal ion binding in less polar solvents. Their cation-binding properties were used for the Finkelstein reaction and the design of new cation-binding hosts.

DOI： 10.1039/D2CC00361A

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The asymmetric oxidation of a sulfur-containing nine-membered heterocycle was achieved for the late-stage introduction of chirality to the substituents of π-electron systems.

DOI： 10.1039/D1CC06996A

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DOI： 10.26434/chemrxiv-2022-2qnp0

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Layer flexibility in two-dimensional coordination polymers (2D-CPs) contributes to several functional materials as it results in anisotropic structural response to external stimuli. Chemical modification is a common technique for modifying layer structures. This study demonstrates that crystal morphology of a cyanide-bridged 2D-CP of type [Mn(salen)]2[ReN(CN)4] (1) consisting of flexible undulating layers significantly impacts the layer configuration and assembly. Nanoplates of 1 showed an in-plane contraction of layers with a longer interlayer distance compared to the micrometer-sized rod-type particles. These effects by crystal morphology on the structure of the 2D-CP impacted the structural flexibility, resulting in dual-functional changes: the enhancement of the sensitivity of structural transformation to water adsorption and modification of anisotropic thermal expansion of 1. Moreover, the nanoplates incorporated new adsorption sites within the layers, resulting in the uptake of an additional water molecule compared to the micrometer-sized rods.

DOI： 10.1002/chem.202103404

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What particular mechanical properties can be expected for materials composed of interlocked backbones has been a long-standing issue in materials science since the first reports on polycatenane and polyrotaxane in the 1970s(1-3). Here we report a three-dimensional porous metal-organic crystal, which is exceptional in that its warps and wefts are connected only by catenation. This porous crystal is composed of a tetragonal lattice and dynamically changes its geometry upon guest molecule release, uptake and exchange, and also upon temperature variation even in a low temperature range. We indented(4) the crystal along its a/b axes and obtained the Young's moduli of 1.77 +/- 0.16 GPa in N,N-dimethylformamide and 1.63 +/- 0.13 GPa in tetrahydrofuran, which are the lowest among those reported so far for porous metal-organic crystals(5). To our surprise, hydrostatic compression showed that this elastic porous crystal was the most deformable along its c axis, where 5% contraction occurred without structural deterioration upon compression up to 0.88 GPa. The crystal structure obtained at 0.46 GPa showed that the catenated macrocycles move translationally upon contraction. We anticipate our mechanically interlocked molecule-based design to be a starting point for the development of porous materials with exotic mechanical properties. For example, squeezable porous crystals that may address an essential difficulty in realizing both high abilities of guest uptake and release are on the horizon.A rubber-like, metal-organic crystal is reported with a mechanically interlocked catenane backbone, which could allow for easy guest molecule uptake and release.

DOI： 10.1038/s41586-021-03880-x

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Multicomponent crystallization is universally important in various research fields including materials science as well as biology and geology, and presents new opportunities in crystal engineering. This process includes multiple kinetic and thermodynamic events that compete with each other, wherein “external triggers” often help the system select appropriate pathways for constructing desired structures. Here we report an unprecedented finding that a lattice strain accumulated with the growth of a crystal serves as an “internal trigger” for pathway selection in multicomponent crystallization. We discovered a “spontaneous” crystal transition, where the kinetically preferred layered crystal, initially formed by excluding the pillar component, carries a single dislocation at its geometrical center. This crystal “spontaneously” liberates a core region to relieve the accumulated lattice strain around the dislocation. Consequently, the liberated part becomes dynamic and enables the pillar ligand to invade the crystalline lattice, thereby transforming into a thermodynamically preferred pillared-layer crystal.

DOI： 10.1021/jacs.1c06854

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DOI： 10.1021/jacs.1c06331

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DOI： 10.1021/acs.joc.1c01155

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<p>The alkyl decorated MOF Zn₂(TM-bdc)₂(dabco) shows good adsorption selectivity towards ethane over ethylene, which was revealed by breakthrough, coadsorption and high pressure adsorption.</p>

DOI： 10.1039/D1DT01477C

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DOI： 10.1021/jacs.1c03268

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Triplet carbenes (TCs) are of great interest due to their magnetic properties and reactivity, which descend from TCs' unique electronic state. However, the reactivity and stability of TCs are usually a trade-off, and it is difficult to achieve both at the same time. In this work, we were able to enhance the thermal stability of a TC species while maintaining its reactivity by confining them in the nanospace of a metal-organic framework (MOF). We synthesized a new MOF using a TC precursor; subsequently, TCs were generated by photostimulation. The TCs generated in the MOF nanospace were detectable up to 170 K, whereas their non-MOF-confined counterparts (bare ligand) could not be detected above 100 K. In addition, the reactivity of TC generated in MOF with O-2 was drastically improved compared to that of bare ligand. Our approach is generally applicable to the stabilization of highly reactive species, whose reactivity needs to be preserved.

DOI： 10.1021/jacs.1c02430

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DOI： 10.1002/ejic.202100172

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We present a systematic study on the support effect of metal-organic frameworks (MOFs), regarding substrate adsorption. A remarkable enhancement of both catalytic activity and selectivity for the ethanol (EtOH) production reaction through acetic acid (AcOH) hydrogenation (AH) was observed on Pt nanoparticles supported on MOFs. The systematic study on catalysis using homogeneously loaded Pt catalysts, in direct contact with seven different MOF supports (MIL-125-NH2, UiO-66-NH2, HKUST-1, MIL-101, Zn-MOF-74, Mg-MOF-74, and MIL-121) (abbreviated as Pt/MOFs), found that MOFs having a high affinity for the AcOH substrate (UiO-66-NH2 and MIL-125-NH2) showed high catalytic activity for AH. This is the first demonstration indicating that the adsorption ability of MOFs directly accelerates catalytic performance using the direct contact between the metal and the MOF. In addition, Pt/MIL-125-NH2 showed a remarkably high EtOH yield (31% at 200 °C) in a fixed-bed flow reactor, which was higher by a factor of more than 8 over that observed for Pt/TiO2, which was the best Pt-based catalyst for this reaction. Infrared spectroscopy and a theoretical study suggested that the MIL-125-NH2 support plays an important role in high EtOH selectivity by suppressing the formation of the byproduct, ethyl acetate (AcOEt), due to its relatively weak adsorption behavior for EtOH rather than AcOH.

DOI： 10.1021/acsami.1c01100

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The layered structures of graphite and related nanographene molecules play key roles in their physical and electronic functions. However, the stacking modes of negatively curved nanographenes remain unclear, owing to the lack of suitable nanographene molecules. Herein, we report the synthesis and one-dimensional supramolecular self-assembly of negatively curved nanographenes without any assembly-assisting substituents. This curved nanographene self-assembles in various organic solvents and acts as an efficient gelator. The formation of nanofibers was confirmed by microscopic measurements, and an unprecedented double-helix assembly by continuous π-πstacking was uncovered by three-dimensional electron crystallography. This work not only reports the discovery of an all-sp2-carbon supramolecular π-organogelator with negative curvature but also demonstrates the power of three-dimensional electron crystallography for the structural determination of submicrometer-sized molecular alignment.

DOI： 10.1021/jacs.1c00863

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DOI： 10.1021/acs.inorgchem.0c03420

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A heterometallic one-dimensional (1-D) chain consisting of multiple kinds of metals, Rh, Pt, and Pd, with direct metal-metal bonds was successfully obtained by mixing a Rh dinuclear complex and Pt-Pd-Pt trinuclear complex. The Pt-Pd-Pt trinuclear complex can be reversibly one-electron-oxidized or -reduced, where the electron paramagnetic resonance spectrum of the one-electron-oxidized one shows an axially symmetric signal with hyperfine splitting by two Pt and Pd, indicating that an unpaired electron is delocalized to the di, orbital of Pt-Pd-Pt. Utilized with the highest occupied molecular orbital and lowest unoccupied molecular orbital interaction at the dz, orbital, simple mixing of the Pt-Pd-Pt trinuclear complex and Rh dinuclear complex in adequate solvents afforded heterometallic 1-D chains, which are aligned as -Rh-Rh-Pt-Pd-Pt-. Several physical measurements revealed that the metal oxidation state is +2. Diffuse reflectance spectra and theoretical calculations show that heterometallic 1-D chains have sigma-type conduction and valence bands where pi*(Rh2) are lying between them, whose gaps become narrower than the prototype chains aligned as -Rh-Rh-Pt-Pt-Pt-Pt-. The narrower band gaps are induced by destabilization of the 6-type valence bands and accompanied by insertion of Pd ions because the d-orbital energy level of Pd is closer in value to Rh compared with Pt. Flash-photolysis time-resolved microwave conductivity measurements exhibited an increase in the product of charge carrier mobility and its generation efficiency (8.1 x 10(-5) to 4.6 x 10(-4) cm(2) s(-1)) with narrowing the band gaps, suggesting that the better conductivity is attributed to shorter metal-metal distances in 1-D chains. These results imply the possibilities of controlling band gap with ligand modification and third metal insertion in heterometallic 1-D chains to show various conductivities.

DOI： 10.1021/acsomega.0c04317

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DOI： 10.1002/smll.202004351

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<title>Abstract</title>
The selective carbon dioxide (CO₂) absorption properties of ionic liquids (ILs) are highly pertinent to the development of methods to capture CO₂. Although it has been reported that fluorinated components give ILs enhanced CO₂ solubilities, it has been challenging to gain a deep understanding of the interactions occurring between ILs and CO₂. In this investigation, we have utilized the soft crystalline material [Cu(NTf₂)₂(bpp)₂] (NTf₂^‒ = bis(trifluoromethylsulfonyl)imide, bpp = 1,3-bis-(4-pyridyl)propane) as a surrogate for single-crystal X-ray diffraction analysis to visualize interactions occurring between CO₂ and NTf₂^‒, the fluorinated IL component that is responsible for high CO₂ solubility. Analysis of the structure of a CO₂-loaded crystal reveals that CO₂ interacts with both fluorine and oxygen atoms of NTf₂^‒ anions in a <italic>trans</italic> rather than <italic>cis</italic> conformation about the S–N bond. Theoretical analysis of the structure of the CO₂-loaded crystal indicates that dispersion and electrostatic interactions exist between CO₂ and the framework. The overall results provide important insight into understanding and improving the CO₂ absorption properties of ILs.

DOI： 10.1038/s42004-020-00390-1

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DOI： 10.1002/anie.202008187

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A photochemically crushable and regenerative metal-organic framework ((MOF)-M-DTE) was developed by complexation of photochromic ligand (DTEopen)-D-Py and 5-nitroisophthalate (nip(2-)) with Cd2+ in DMF/MeOH. (MOF)-M-DTE ([Cd(nip)((DTEopen)-D-Py)-(H2O)(DMF)(2)](n)) was obtained as colorless crystals. Its crystal structure revealed that (MOF)-M-DTE adopts a tubular structure with interlocked coordination networks and can accommodate guest molecules in its one-dimensional pores. When (MOF)-M-DTE suspended in DMF/MeOH was exposed to UV light, its crystalline network, though thermally stable up to 260 degrees C, was readily crushed to afford a homogeneous blue-colored solution, via ring-closing isomerization of the constituent (DTEopen)-D-Py ligand into (DTEclosed)-D-Py. Upon successive exposure of this solution to visible light, colorless MOF crystals identical to those of (MOF)-M-DTE were regenerated. Light-responsive (MOF)-M-DTE enabled highly efficient on-demand guest release.

DOI： 10.1021/jacs.0c06615

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DOI： 10.1021/acsami.9b21261

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Metal-organic frameworks (MOFs) are known as promising adsorbent materials that can recognize gases specifically. In the frameworks, gases favor interacting with specific binding sites such as open metal sites (OMSs), which can consist of various metals and show characteristic adsorption properties. A recently reported framework possessing OMSs of rhodium paddle-wheel (Rh-PW) showed distinct adsorption properties between NO and CO. We investigated theoretically the reasons for stronger NO binding to the Rh-PW and different adsorption amounts between NO and CO using Rh-PW cluster models, as well as the frequently reported Cu-PW for comparison. We also analyzed the cases of CO2 and N-2, which are often used to probe functions of MOFs. We observed an increase in binding energy of NO at the second adduction of NO. On the basis of energy decomposition analysis, we found that Rh-NO bond formation inducing a trans influence is important for the stronger binding than with CO. Furthermore, we proposed a reason for twice the adsorption amount of NO than CO. The results are consistent with experimental observations, giving us insight into design functions of MOFs by selecting metal species.

DOI： 10.1021/acs.inorgchem.9b02911

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<p>A fluorophore encapsulated in a metal–organic framework showed photochromic multicolour fluorescence.</p>

DOI： 10.1039/D0CC03624B

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<p>The solid solutions composed of different ratios of two Werner complexes showed controlled acetone gate-sorption properties.</p>

DOI： 10.1039/D0DT01355B

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Deracemization is a powerful method by which a racemic mixture can be transformed into an excess of one enantiomer with the aid of chiral auxiliaries, but has been applied only to small chiral molecular systems. Here we report a deracemization of a racemic double-stranded spiroborate helicate containing a bisporphyrin unit upon encapsulation of chiral aromatic guests between the bisporphyrin. The chiral guest-included helicate is kinetically stable, existing as a mixture of right- and left-handed double helices, which eventually undergo an inversion of the helicity triggered by water resulting from the water-mediated reversible diastereoselective B-O bond cleavage/reformation of the spiroborate groups, thus producing an optically-active helicate with a high enantioselectivity. Quantum chemical calculations suggest that the stereospecific CH-pi interactions between the porphyrin hydrogen atoms of the helicate and an aromatic pendant group of the chiral guest play a key role in the enhancement of the helical handedness of the helicate.

DOI： 10.1038/s41467-019-09443-z

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A layered metal-organic framework (MOF) comprising extra-large nanographene sheets, (MOF)-M-HBC, was successfully synthesized using a dicarboxylic acid derivative of hexa-perihexab enzocoronene ((LH2)-L-HBC), and its structure was characterized by single-crystal X-ray diffraction analysis. The crystal structure shows that 2D layers composed of a dinuclear Zn2+ complex unit and L-HBC are located on top of each other through multiple weak interlayer bonds, affording (MOF)-M-HBC, having three dimensionally connected nanopores with large nanographene surfaces. The HBC-based nanographene sheets are anchored to the MOF framework via two zinc carboxylate linkages and therefore have an axial rotational freedom. The sorption isotherms of gaseous molecules such as carbon dioxide and hydrocarbons (acetylene, propane, propylene, benzene, and cyclohexane) on (MOF)-M-HBC all displayed a hysteretic profile with reversible structural changes, as observed by in situ powder X-ray diffraction studies.

DOI： 10.1021/jacs.9b07732

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DOI： 10.1021/jacs.9b07682

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The generation of topologically complex nanocarbons can spur developments in science and technology. However, conventional synthetic routes to interlocked molecules require heteroatoms. We report the synthesis of catenanes and a molecular trefoil knot consisting solely of para-connected benzene rings. Characteristic fluorescence of a heterocatenane associated with fast energy transfer between two rings was observed, and the topological chirality of the all-benzene knot was confirmed by enantiomer separation and circular dichroism spectroscopy. The seemingly rigid all-benzene knot has rapid vortex-like motion in solution even at -95 degrees C, resulting in averaged nuclear magnetic resonance signals for all hydrogen atoms. This interesting dynamic behavior of the knot was theoretically predicted and could stimulate deeper understanding and applications of these previously untapped classes of topological molecular nanocarbons.

DOI： 10.1126/science.aav5021

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The self-assembly of an amide-functionalized dithienyldiketopyrrolopyrrole (DPP) dye in aqueous media was achieved through seed-initiated supramolecular polymerization. Temperature- and time-dependent studies showed that the spontaneous polymerization of the DPP derivative was temporally delayed upon cooling the monomer solution in a methanol/water mixture. Theoretical calculations revealed that an amide-functionalized DPP derivative adopts an energetically favorable folded conformation in the presence of water molecules due to hydration. This conformational change is most likely responsible for the trapping of monomers in the initial stage of the cooperative supramolecular polymerization in aqueous media. However, the monomeric species can selectively interact with externally added fragmented aggregates as seeds through concerted pi-stacking and hydrogen-bonding interactions. Consequently, the time course of the supramolecular polymerization and the morphology of the aggregated state can be controlled, and one-dimensional fibers that exhibit a J-aggregate-like bathochromically shifted absorption band can be obtained.

DOI： 10.1002/chem.201901382

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DOI： 10.1002/jcc.25856

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DOI： 10.1002/jcc.25610

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<p>Consecutive oxidative additions of iodine on the undulating 2D coordination polymer produced unprecedented anisotropic structures.</p>

DOI： 10.1039/c8dt04624g

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DOI： 10.1039/C8CP06159A

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DOI： 10.1039/C8DT04218G

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The parasitic plant Striga hermonthica has been causing devastating damage to the crop production in Africa. Because Striga requires host-generated strigolactones to germinate, the identification of selective and potent strigolactone agonists could help control these noxious weeds. We developed a selective agonist, sphynolactone-7, a hybrid molecule originated from chemical screening, that contains two functional modules derived from a synthetic scaffold and a core component of strigolactones. Cooperative action of these modules in the activation of a high-affinity strigolactone receptor ShHTL7 allows sphynolactone-7 to provoke Striga germination with potency in the femtomolar range. We demonstrate that sphynolactone-7 is effective for reducing Striga parasitism without impinging on host strigolactone-related processes.

DOI： 10.1126/science.aau5445

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Nature Publishing Group  

Precise fabrication of molecular assemblies on a solid surface has long been of central interest in surface science. Their perfectly oriented growth only along a desired in-plane direction, however, remains a challenge, because of the thermodynamical equivalence of multiple axis directions on a solid-surface lattice. Here we demonstrate the successful fabrication of an in-plane, unidirectional molecular assembly on graphene. Our methodology relies on nanomechanical symmetry breaking effects under atomic force microscopy tip scanning, which has never been used in molecular alignment. Individual one-dimensional (1D) molecular assemblies were aligned along a selected symmetry axis of the graphene lattice under finely-tuned scanning conditions after removing initially-adsorbed molecules. Experimental statistics and computational simulations suggest that the anisotropic tip scanning locally breaks the directional equivalence of the graphene surface, which enables nucleation of the unidirectional 1D assemblies. Our findings will open new opportunities in the molecular alignment control on various atomically flat surfaces.

DOI： 10.1038/s41598-018-20760-z

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Genistein is an isoflavone with promising pharmaceutical applications. However, its low water solubility interferes with its potency, and therefore cyclodextrins (CDs) have been considered as possible drug delivery system (DDS). To investigate the complexation mechanism of genistein in cyclodextrin, we employed molecular dynamics (MD) simulations based on classical potentials and the density-functional tight-binding (DFTB) quantum chemical potential. Both classical and quantum chemical MD simulations predict that the phenol ring of genistein is preferentially complexed in the cavity of CD. The complexation process reduces the water-accessible solvation shell, and it is found that a hydrogen bond is formed between genistein and CD. The DFTB-based MD simulations reveal that spontaneous keto-enol tautomerization occurs even within a hundred picoseconds, which suggests that the encapsulated genistein is complexed in the ordinary enol form of the drug molecule. Analyses of the molecular charge distributions suggest that electrostatic interactions partially induce the complex formation, rather than extensive formation of hydrogen bonds.

DOI： 10.1016/j.molliq.2018.05.109

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A spontaneous entrapment of electron-donating small guest molecules, including tetrathiafulvalene (TTF) and N,N,N′,N′-tetramethyl-1,3-propanediamine (TMPDA), was realized in a structurally flexible metal-organic framework, {Mn7(2,7-AQDC)6(2,6-AQDC)(DMA)6}∞ (AQDC = anthraquinone dicarboxylates, DMA = N,N-dimethylacetamide), with electron-accepting anthraquinone groups, generating two MOF guest charge transfer complexes: {Mn7(2,7-AQDC)6(2,6-AQDC)(DMA)6(TTF)5} and {Mn7(2,7-AQDC)6(2,6-AQDC)(DMA)4(H2O)2(TMPDA)7}. Using a mild impregnation procedure, single crystals of the target complexes were obtained via a crystal-to-crystal conversion, and the crystals were suitable for structural analysis. Single crystal X-ray analysis demonstrated the different arrangements of these intercalated donor molecules: some donor molecules interacted with the anthraquinone groups and formed infinite D-A-A-D stacks, some appeared beside the anthraquinone groups but only formed donor-acceptor pairs, and the remainder of the molecules simply filled the space. The charge transfer between the guests and the framework was spectroscopically confirmed, and the radical densities on the organic species were estimated using magnetic susceptibility measurements. Compared with a solid-state mixture of anthraquinone and donor molecules, the evenly distributed donor molecules in the micropores of the MOF resulted in a "solid solution" state and significantly promoted the degree of charge transfer between donors and acceptors. Such an encapsulation process may be adopted as a new strategy for post-modification of the electronic and magnetic properties of MOFs, as well as for generating new semiconducting charge-transfer complexes.

DOI： 10.1039/c7sc05390h

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society  

With the rapidly diminishing fossil fuel resources, development of a new strategy for synthesis of biofuels from renewable resources can provide a sustainable alternative to our energy demand. We present the design, synthesis, and characterization of a new porous organic network (TpPON) through acid-catalyzed condensation of 1,3,5-triformylphloroglucinol (Tp) and triphenylamine (TPA). Ru0 nanoparticles are successfully fabricated at the porous surface of TpPON to obtain a novel catalytic system Ru@TpPON, which exhibits excellent catalytic performance together with outstanding stability for the hydrodeoxygenation of various vegetable oils to long-chain alkanes in water, and thus TpPON has wide potential for large-scale biodiesel production from renewable resources.

DOI： 10.1021/acssuschemeng.7b02772

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The new porous polymer TPDA-1 has been synthesized via solvothermal Schiff base condensation reaction between two organic monomers, i.e., 2,4,6-trihydroxyisophthalaldehyde and 1,3,5-tris(4-aminophenyl)triazine. The TPDA-1 material showed a very high specific capacitance of 469.4 F g-1, at 2 mV s-1 scan rate, together with a high specific surface area of 545 m2 g-1. It also exhibited excellent cyclic stability with 95% retention of its initial specific capacitance after 1000 cycles at 5 A g-1, suggesting its potential as a high performance supercapacitor. Extended π-conjugation and ion conduction inside the micropores throughout the whole polymeric matrix and high BET surface area could be responsible for this high supercapacitor performance in energy storage device. TPDA-1 has been characterized thoroughly by various electrochemical techniques such as cyclic voltammetry, galvanic charge-discharge, and electrochemical impedance spectroscopy. Our experimental results suggested a high potential of this porous polymer in energy storage devices for future generation.

DOI： 10.1021/acssuschemeng.7b02234

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© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. The sulfur-containing nine-membered heterocycle thiacyclononene (TN) was evaluated as a new type of endcapping group for π-conjugated systems. A systematic study on TN-capped α-oligothiophenes (TNnTs; n=4–7) revealed that the capping with TN, which adopts a bent conformation, imparts the resulting oligothiophenes with drastically increased solubility at approximately 140oC and high electrochemical stability, whereas the electronic structure remains virtually unperturbed. The even-numbered oligothiophenes TN4T and TN6T form characteristic offset herringbone-type packing structures on account of the steric repulsion between the TN rings and the presence of intermolecular nonbonding S···S interactions. This packing mode in combination with the high solubility enabled the solutionprocess fabrication of field-effect transistors based on TN6T, which exhibited a high performance without degradation even upon exposure to air.

DOI： 10.1002/chem.201802656

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Copyright © 2018 American Chemical Society. Monolayer molybdenum disulfide (MoS2) is an atomically thin semiconducting material with a direct band gap. This physical property is attributable to atomically thin optical devices such as sensors, light-emitting devices, and photovoltaic cells. Recently, a near-unity photoluminescence (PL) quantum yield of a monolayer MoS2 was demonstrated via a treatment with a molecular acid, bis(trifluoromethane)sulfonimide (TFSI); however, the mechanism still remains a mystery. Here, we work on PL enhancement of monolayer MoS2 by treatment of Brønsted acids (TFSI and sulfuric acid (H2SO4)) to identify the importance of the protonated environment. In TFSI as an acid, different solvents - 1,2-dichloroethane (DCE), acetonitrile, and water - were studied, as they show quite different acidity in solution. All of the solvents showed PL enhancement, and the highest was observed in DCE. This behavior in DCE would be due to the higher acidity than others have. Acids from different anions can also be studied in water as a common solvent. Both TFSI and H2SO4 showed similar PL enhancement (∼4-8 enhancement) at the same proton concentration, indicating that the proton is a key factor to enhance the PL intensity. Finally, we considered another cation, Li+ from Li2SO4, instead of H2SO4, in water. Although Li and H atoms showed similar binding energy on MoS2 from theoretical calculations, Li2SO4 treatment showed little PL enhancement; only coexisting H2SO4 reproduced the enhancement. This study demonstrated the importance of a protonated environment to increase the PL intensity of monolayer MoS2. The study will lead to a solution to achieve high optical quality and to implementation for atomically thin optical devices.

DOI： 10.1021/acs.langmuir.8b01425

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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：WILEY-V C H VERLAG GMBH  

We attempted the synthesis and crystallographic characterization of light-metal coordination polymers (CPs) using a 4-(methylsulfonyl)benzoate (msbza(-)) ligand with a charge-polarized neutral methylsulfonyl coordination moiety, in order to diversify the limited structures of light-metal CPs, as compared with heavy-metal CPs. As expected from the results of DFT calculations, all of the obtained CPs {three-dimensional (3D) [Mg2Na2(msbza)(6)(H2O)(3)](n) (1), two-dimensional (2D) [KH(msbza)(2)](n) (2) and 2D [Na(msbza)](n) (3)} exhibited coordination of the methylsulfonyl moiety to light-metal cations, in addition to coordination of the carboxylate. These structural features suggest that the use of a neutral methylsulfonyl coordination site is a powerful tool for the structural diversification of light-metal CPs. In addition, the 3D CP 1, with the rare and unique tetranuclear Mg2Na2 secondary building unit, showed an unprecedented single-crystal-to-single-crystal transformation via the low-crystalline state.

DOI： 10.1002/ejic.201700627

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Numerous otherwise difficult applications have been realized with materials, the chemical/physical properties of which can be controlled by external stimuli such as heat, pressure, photo-irradiation, and voltage bias. However, the complexity of design and the lack of easy-to-conduct synthetic methods make the creation of on-demand stimuli responsive materials a formidable task. Here we report an electric-stimuli-responsive multifunctional material, [10]CPP-I: crystalline assembly of a hydrocarbon nanoring ([10]cycloparaphenylene: [10]CPP) as an "electro-responsive porous host" and iodine as a "potentially functional molecule". Through applying electric stimulus, [10]CPP-I turned to exhibit two attractive properties: electronic conductivity and white light emission. We revealed that electric stimuli trigger the cascade formation of polyiodide chains inside the [10]CPP assembly through charge transfer, leading to the emergence of these properties. This "responsive porous host" approach is expected to be applicable for different stimuli, and opens the path for devising a generic strategy to the development of stimuli-responsive materials.

DOI： 10.1002/anie.201703648

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DOI： 10.1021/acs.jpcc.7b03627

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DOI： 10.1021/acs.jpcc.7b0362

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DOI： 10.1002/qua.25371

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Sulfonic acid (-SO3H) functionalized anthracene derived conjugated porous organic polymer (AnPOP-SO3H) have been constructed through Friedel-Crafts alkylation of anthracene by using formaldehyde dimethyl acetal as a cross-linker and anhydrous FeCl3 as a promoter followed by sulfonation of aromatic rings using chlorosulfonic acid under controlled reaction conditions. Morphological evolution, porous structure, nature and strength of the acid sites and structural integrity with different chemical environments have been comprehensively examined by employing HR-TEM (High Resolution Transmission Electron Microscopy), FE-SEM (Field Emission-Scanning Electron Microscopy), Powder X-ray diffraction, N-2 sorption, NH3-TPD (Temperature Programmed Desorption), solid state C-13 CP MAS-NMR (Cross Polarization Magic Angle Spinning-Nuclear Magnetic Resonance), HAADF-STEM (High Angle Annular Dark Field-Scanning Transmission Electron Microscopy) with the corresponding elemental mapping and FT-IR (Fourier Transform Infrared) spectroscopic tools. This newly designed AnPOP-SO3H metal-free organocatalyst exhibited an excellent catalytic activity in the acetalization of Bio-Glycerol with acetone, furfural, and benzaldehyde under solvent free and ambient temperature conditions to furnish 2,2-dimethyl-1,3-dioxalane-4-methanol (solketal) derivatives, with quantitative conversion and good selectivities. An enhancement in the catalytic performance of the nanohybrid metal-free solid acid catalyst is observed compared with the conventional reported catalysts which could be attributed to the presence of high acidic sites, huge surface area accompanied with the highly rigid cross linked framework thereby facilitating easy diffusion of organic substrates to interact with the catalytic active sites and prohibiting water diffusion inside the pore owing to the hydrophobic nature of the catalyst. The investigated AnPOP-SO3H represents a novel class of promising heterogeneous metal-free organocatalyst with ten recycles in succession and no sign of catalyst deactivation, useful for the transformation of Bio-Glycerol to value-added chemicals in an eco-friendly manner for future industry.

DOI： 10.1002/slct.201700901

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

Molecular carbon nanorings, [n]cycloparaphenylenes ([n]CPP), are a unique class of porous molecules with allbenzene surface. Herein, we report the preparation of polymorphs of [6] CPP crystals for the first time, and the discovery of their packing structure-dependent properties. We found that the herringbone-packed structure is thermodynamically more stable than the tubular-packed structure. We revealed that their host-guest interaction depends on the packing structures of [6] CPP: the tubular-packing affords one-dimensional open channels for weak guest sorption, while the herringbone-packing gives closed cavities for strong guest entrapment. This study exemplifies that the solid-state host-guest chemistry of CPP crystals can be directed by controlling their packing structures.

DOI： 10.1246/cl.170210

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DOI： 10.1021/axsami.7b01568

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Novel double helices covalently bridged by cyclic boronate esters were synthesized from complementary dimers with an m-terphenyl backbone joined by a chiral or achiral phenylene linker bearing diethyl boronates and diols, respectively. The X-ray crystallographic analysis and variable-temperature NMR and circular dichroism measurements, along with theoretical calculations, revealed that the double helices function as a molecular rotor in which the cyclic boronate ester units rotate, yielding two stable rotamers at low temperatures. Moreover, our data indicates that the covalently bonded double helices can undergo a unique helix-inversion simultaneously with a rotational motion of the boronate esters.

DOI： 10.1002/asia.201700162

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DOI： 0.1002/qua.25371

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DOI： 10.1246/c1.170210

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DOI： 10.1016/j.chempr.2017.02.002

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

Slight changes in the coordination structure of the manganese(V)-nitrido anionic complex, [Mn-V(N) (CN)(4)](2-), induced by using a "lipid package" approach markedly made an impact on the corresponding redox potentials. The single crystals of four lipid assemblies, [dabco-(CH2)(n-1)-CH3](2)[Mn(N)(CN)(4)(H2O)]center dot xH(2)O (n = 15, 16, 17 and 18; dabco = 1,4-diazabicyclo[2,2,2] octane), were synthesized and solid-state cyclic voltammetric studies demonstrated that the [Mn-V(N)(CN)(4)](2)-anions with smaller "cross" NC-Mn-CN bond angles exhibit higher redox potentials. The observed trend reflects the energy change associated with the structural transformation from [Mn-V(N)(CN)(4)](2-)to [ Mn-VI(N)(CN)(4)](2-) and is supported by the results of DFT calculations. The NC-Mn-CN bond angles in the flexible [Mn(N)(CN)(4)](2-) structure exhibit excellent correlation with the redox potentials of the complexes in the solid state.

DOI： 10.1039/c7dt00233e

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

The new covalent organic framework material TDFP-1 was prepared through a solvothermal Schiff base condensation reaction of the monomers 1,3,5-tris-(4-aminophenyl) triazine and 2,6-diformyl-4-methylphenol. Owing to its high specific surface area of 651 m(2)g(-1), extended pi conjugation, and inherent microporosity, TDFP-1 exhibited an excellent energy-storage capacity with a maximum specific capacitance of 354 Fg(-1) at a scan rate of 2 mVs(-1) and good cyclic stability with 95% retention of its initial specific capacitance after 1000 cycles at 10 Ag-1. The pi-conjugated polymeric framework as well as ionic conductivity owing to the possibility of ion conduction inside the micropores of approximately 1.5 nm make polymeric TDFP-1 a favorable candidate as a supercapacitor electrode material. The electrochemical properties of this electrode material were measured through cyclic voltammetry, galvanic charge-discharge, and electrochemical impedance spectroscopy, and the results indicate its potential for application in energy-storage devices.

DOI： 10.1002/cssc.201601571

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society  

A new porous coordination polymer (PCP) based on a ligand with a unique bent angle bearing a thiophene-bridged bent carboxylate ligand and the Cu2+ ion was synthesized and structurally characterized. The structure has a pillared-layer framework based on a kagomé-like layer with aromatic partition groups. It exhibits a high CO2 uptake of 180 mL(STP)/g at 1 bar, and 400 mL(STP)/g at 30 bar at 273 K. The uptakes of C2H2 and C2H4 reach 164 and 160 mL(STP)/g at 298 K and 1 bar, with good selectivity of C2H2 and C2H4 over CH4, both of which are among the highest levels of reported PCPs.

DOI： 10.1021/acsami.7b01568

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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：AMER CHEMICAL SOC  

Density functional theory is employed to demonstrate how ammonia derived etchant radicals (H, NH, and NH2) can be used to promote particular (n,m) chirality single-walled carbon nanotube (SWCNT) caps during chemical vapor deposition (CVD) growth. We reveal that the chemical reactivity of these etchant radical species with SWCNTs depends on the SWCNT chirality. This reactivity is determined by the extent of disruption to the pi-conjugation of the cap structure caused by reaction with the etchant species. H and NH2 attack single carbon atoms and preferentially react with near-zigzag SWCNT caps, whereas NH prefers to attack across C-C bonds and selectively etches near-armchair SWCNT caps. We derive a model for predicting abundances of (n,m) SWCNTs in the presence of ammonia-derived radicals, which is consistent with (n,m) distributions observed in recent CVD experiments with ferrocene and ammonia. This model also demonstrates that chiral-selective etching of SWCNTs during CVD growth can be potentially exploited for achieving chirality control in standard CVD synthesis.

DOI： 10.1021/acs.jpcc.6b06997

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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：ROYAL SOC CHEMISTRY  

The molecular carbon nanoring, cycEoparaphenyEene (CPP), is fascinating as a new class of carbonaceous porous solids with the uniform structure of an all-benzene surface. We explored the feasibility of [12]CPP as a carbon-based porous material and uncovered its unique adsorption properties due to its shape and highly non polar surface. Unlike other porous carbon solids, [12]CPP shows stepwise adsorption behaviors sensitive to the functionahties of the guest molecules. In situ powder X-ray diffraction and infrared spectra provided insights into how [12]CPP accommodates the guest molecules with structural deformation retaining its structural periodicity during the whole adsorption process, which exemplifies that this molecular nanoring represents an unprecedented carbon-based soft porous solid.

DOI： 10.1039/c6sc00092d

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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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Rational design to control the dynamics of molecular rotors in crystalline solids is of interest because it offers advanced materials with precisely tuned functionality. Herein, we describe the control of the rotational frequency of rotors in flexible porous coordination polymers (PCPs) using a solid-solution approach. Solid-solutions of the flexible PCPs [{Zn(5-nitroisophthalate)(x)(5-methoxyisophthalate)(1-x)(deuterated 4,4'-bipyridyl)}(DMF-MeOH)](n) allow continuous modulation of cell volume by changing the solid-solution ratio x. Variation of the isostructures provides continuous changes in the local environment around the molecular rotors (pyridyl rings of the 4,4'-bipyridyl group), leading to the control of the rotational frequency without the need to vary the temperature.

DOI： 10.1021/jacs.5b05413

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

Novel organic-inorganic hybrid liposomes, so-called coordination polymersomes (CPsomes), with artificial domains that exhibit strong lateral cohesion were prepared by a three-step procedure that formed a coordinative interaction leading to a lipid bilayer. First, the lipophilic complex (dabco-C-18)[Mn(N)(CN)(4)(dabco-C-18)] (1; dabco-C-18(+)=1,4-diazabicyclo[2,2,2]octane-(CH2)(17)CH3 cation), was synthesized. 1 has a lipophilic alkyl tail part and a tetracyanometallate head group, which can be used for an expansion to two-dimensional coordination networks. Second, 1 and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine were mixed to prepare the liposomes. Finally, CPsomes were obtained by the addition of transition-metal ions (M) to form unilamellar faceted liposomes with plain CP raft domains with MnCNM linkages. The concentration of 1 influences the size of the CP raft domains and the shape of the CPsomes. The synthesis of coordination polymers in lipid bilayers is a novel approach for the construction of artificial architectures as raft domains, for example, in cell membranes.

DOI： 10.1002/anie.201408101

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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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The structure of a glass obtained by the melt quenching of a two-dimensional (2D) coordination network was examined. X-ray analyses disclosed a 2D-to-0D structural transformation before and after glass formation. The mechanism is unique to coordination compounds, as it is characterized by labile and flexible coordination bonds.

DOI： 10.1039/c5cc04626b

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The separation of olefins from paraffin is important for the production of industrial chemicals. Therefore, there is a need for a better separation system such as a pressure-swing adsorption (PSA) process. With regard to adsorbents that enable gas separation by PSA, CPL-1 {[Cu2(2,3-pyrazinedicarboxylate)2(pyrazine)]n} is an attractive porous material because of the flexibility and microporosity of the material, which provides it with a unique guest-responsive nature. Adsorption isotherm studies were conducted to elucidate the ethylene-selective adsorption properties of CPL-1, which was further examined by breakthrough experiments with ethylene-ethane binary gas mixtures at near room temperatures. Spectroscopic and computational approaches used to investigate the interaction between CPL-1 and the C2 gas molecules suggested that hydrogen bonds are important in the selective adsorption of ethylene over ethane.

DOI： 10.1002/ejic.201402085

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We theoretically evaluated binding energies (E-b's) between various gas molecules and the Cu center open metal site (Cu-OMS) of Cu paddle-wheel units, [Cu-2(O2CR)(4)] (R = H, Me, or Ph) using density functional theory (DFT) and MP2-MP4. The optimized geometry of the model system [Cu-2(O2CPh)(4)] agrees with the experimental structure. The E-b of CO with [Cu-2(O2CH)(4)] is only slightly different between the open-shell singlet and triplet states. The calculated E-b decreases in the order MeNC &gt; H2O &gt; MeCN &gt; C2H4 &gt; C2H2 &gt; CO &gt; CO2 &gt; N-2 &gt; CH4 &gt; H-2. The trend is discussed in terms of the electrostatic interaction energy (ES), exchange repulsion energy (EX), and charge-transfer (CT) + polarization (Pol) interaction energy at the Hartree-Fock level and the electron correlation effect. The ES increases linearly with an increase in E-b, while the EX decreases linearly with an increase in E-b. These relationships indicate that the ES compensates for the EX. In other words, the E-b does not depend on the sum of ES and EX, which corresponds to the static energy. The electron correlation effect contributes little to the above-mentioned decreasing order of E-b. The total E-b roughly increases with an increase in the CT+Pol term, suggesting that the CT+Pol term plays important roles in determining the trend of E-b. The shift of the stretching frequency of adsorbed gas molecules on the Cu-OMS is reproduced well by the DFT calculation with the model system [Cu-2(O2CH)(4)(L)(2)] (L = gas molecule). We found that the positive charge on the Cu significantly contributes to the shift in the end-on coordination gas molecules such as CO, MeNC, MeCN, and N-2. Although the shift has been generally discussed in terms of donation and back. donation, the present result indicates that the electrostatic potential field in the porous coordination polymer should be considered in the discussion of the frequency shift.

DOI： 10.1021/ic402172v

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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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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IOP PUBLISHING LTD  

Highly accurate wave functions of the ground and electronic (1s sigma(g) g and 3d sigma(g)), vibrational (v = 0-15 for 1s sigma(g) and v = 0-8 for 3d sigma(g)), and rotational (L = 0-6: S-1, P-3, D-1, F-3, (1)G, H-3, and I-1) excited states of the hydrogen molecular ion were obtained by solving the non-Born-Oppenheimer (non-BO) Schrodinger equation using the free complement (FC) method. The vibronic states belonging to the electronic excited state 3d sigma(g) are embedded in the continuum of the dissociation, H(1s) + H+. Nevertheless, they exist as physical bound states that have negligible coupling with the continuum. The complex scaled Hamiltonian was employed to analyze the bound and/or resonance natures of the obtained eigenstates, and a new resonance state appeared between the above two electronic states. We numerically proved that the FC method is a reliable theoretical tool for investigating non-BO quantum effects, and it should be available for various studies of hydrogen-related space chemistry and low-temperature physics.

DOI： 10.1088/0004-637X/770/2/144

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

The use of divalent Cu-II ions and an anion-mixing method led to the rational construction of a porous coordination polymer bridged by weak Lewis base inorganic CF3SO3- monoanions.

DOI： 10.1021/ic400276c

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We have synthesized four porous coordination polymers (PCPs) using Zn 2+, 4,4′-sulfonyldibenzoate (sdb), and four types of dinitrogen linker ligands, 1,4-diazabicyclo[2,2,2]octane (dabco), 1,4-bis(4-pyridyl) benzene (bpb), 3,6-bis(4-pyridyl)-1,2,4,5-tetrazine (bpt), and 4,4′-bipyridyl (bpy). The bent sdb ligands form a rhombic space connected by zinc paddle-wheel units to form a one-dimensional double chain, and each dinitrogen ligand linked the one-dimensional double chains. There are different assembled structures of two-dimensional sheets with the same connectivities between Zn2+ and the organic ligands. [Zn2(sdb) 2(dabco)]n (1) has a noninterpenetrated and noninterdigitated structure, [Zn2(sdb)2(bpb)]n (2) and [Zn2(sdb)2(bpt)]n (3) have interdigitated structures, and [Zn2(sdb)2(bpy)] n (4) has an interpenetrated structure. The length of the dinitrogen ligands dominated their assembled structures and flexibility, which influence the adsorption properties. The flexible frameworks of 2 and 3 provide different stepwise adsorption behaviors for CO2, CH4, C 2H6, and C2H4 affected by their pore diameters and the properties of the gases. Their different adsorption properties were revealed by IR spectroscopy and X-ray analysis under a gas atmosphere. The framework of 4 possesses less flexibility and a smaller void space than the others and a negligible amount of CH4 was adsorbed; however, 4 can adsorb either C2H6 or C2H 4 through the gate-opening phenomenon. Measurement of the solid-state 2H NMR was also carried out to investigate the relationship between the framework structure and the dynamics of bpy with regard to the lower flexibility of 4. We have demonstrated a strategy to control the pore size and assembled structures toward selective adsorption properties of PCPs. © 2013 American Chemical Society.

DOI： 10.1021/ic302006x

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

High selectivity and low-energy regeneration for adsorption of CO2 gas were achieved concurrently in a two-dimensional Cu(II) porous coordination polymer, [Cu-(PF6)(2)(4,4'-bpy)(2)] (4,4'-bpy = 4,4'-bipyridine), containing inorganic fluorinated PF6- anions that can act as moderate interaction sites for CO2 molecules.

DOI： 10.1021/ic301823j

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

2-D layer type porous coordination polymers containing redox active Fe2+ centers were synthesized. One of the compounds [Fe(isophthalate)(4,4'-bipyridyl)] showed structural flexibility via guest adsorption, and we observed reversible Fe2+ and Fe3+ switching by iodine insertion. The composite showed electric conductivity.

DOI： 10.1039/c3ta01414b

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

We report the syntheses and crystal structures of novel porous assemblies of coordination complexes (PACs) with/without guest molecules, alpha-[Cu(A)(2)(py)(4)] (alpha-PAC-2-A (A = PF6, BF4, CF3SO3, and CH3SO3); py = pyridine), gamma-{[Cu(PF6)(2)(py)(4)]center dot 2guest} (gamma-PAC-2-PF6 superset of 2guest (guest = acetone and py)), gamma-{[Cu(BF4)(2)-(py)(4)]center dot 2acetone} (gamma-PAC-2-BF4 superset of 2acetone), and beta-{[Cu(CH3SO3)(2)(py)(4)]center dot 2.67H(2)O} (beta-PAC-2-CH3SO3 superset of 2.67H(2)O). The single-crystal X-ray diffraction analyses of alpha-PAC-2-A show that alpha-PAC-2-A have dense packing structures, in which anions of the discrete coordination complexes form weak hydrogen-bonding and anion-pi interactions. In contrast, gamma-PAC-2-PF6 superset of 2guest, gamma-PAC-2-BF4 superset of 2acetone, and beta-PAC-2-CH3SO3 superset of 2.67H(2)O form guest-including structures with coordination environments around the Cu-II atoms similar to the a-forms. The vapour adsorption measurements for MeCN and acetone in alpha-PAC-2-A suggest that the adsorption associated with structural transformations is induced by weak Lewis-base PF6- and BF4- anions covered only with fluorine atoms, which weaken the host-host interactions.

DOI： 10.1039/c3dt51104a

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

Porous substances, including crystalline coordination materials and an amorphous organic polymer, were studied for their selective adsorption of siloxane D4. The investigated materials demonstrated a level of uptake comparable to that of conventional activated carbon.

DOI： 10.1039/c3ta11217a

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A quasielastic neutron scattering and solid-state H-2 NMR spectroscopy study of the polymeric spin-crossover compound {Fe(pyrazine)[Pt(CN)(4)]} shows that the switching of the rotation of a molecular fragment- the pyrazine ligand-occurs in association with the change of spin state. The rotation switching was examined on a wide time scale (10(-13)-10(-3) s) by both techniques, which clearly demonstrated the combination between molecular rotation and spin-crossover transition under external stimuli (temperature and chemical). The pyrazine rings are seen to perform a 4-fold jump motion about the coordinating nitrogen axis in the high-spin state. In the low-spin state, however, the motion is suppressed, while when the system incorporates benzene guest molecules, the movements of the system are even more restricted.

DOI： 10.1021/ja206228n

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By adopting a ligand-based solid solution approach, the sulphonic acid functional group can be successfully incorporated into a porous coordination polymer with UiO-66 structure type. Zr6O4(OH)(4)(BDC-SO3H)(1.1)(BDC)(4.9) possesses enhanced heat of adsorption for carbon dioxide and acetone compared to Zr6O4(OH)(4)(BDC)(6).

DOI： 10.1039/c2dt31195j

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

DOI： 10.1002/anie.201203834

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DOI： 10.1038/NMAT3104

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

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  

Systematic functionalization of porous coordination polymers (PCPs), [Cu(2)(L)(2)(ted)](n) (where L = dicarboxylates and ted = triethylenediamine), by introducing various substituents onto the component organic ligand, L, was performed to regulate the radical polymerization of methyl methacrylate (MMA) in the nanochannels. The effect of the substituent groups on stereoregularity of the resulting poly(methyl methacrylate) (PMMA) was observed, where the tacticity of the PMMA strongly depended on the number and position of the substituent. In particular, polymerization of MMA in [Cu(2)(2,5-dimethoxyterephthalate)(2)(ted)](n) gave PMMA with high isotactic and heterotactic triad fractions, which is one of the most effective systems for changing the tacticity of PMMA in radical polymerization. To understand the mechanism of this drastic stereoregularity change, a variety of experimental and theoretical analyses, such as IR, N(2) adsorption, a statics study, and molecular dynamics (MD) calculations, were performed. Accurate MD calculations were helpful to determine the most plausible structures of [Cu(2)(L)(2)(ted)](n) and revealed that the specific channel shape of [Cu(2)(2,5-dimethoxyterephthalate)(2)(ted)](n) induces the large tacticity change of the resulting PMMA.

DOI： 10.1021/ja100406k

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We have synthesized a porous coordination polymer containing a pyridinium cation as an organic linker and have investigated the methanol absorptive ability of the pyridinium cationic surface. The result implies that the pyridinium cationic surface participates in the strong adsorption of methanol.

DOI： 10.1021/ja900373v

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We investigated the concept "charge-polarized coordination spaces" in porous coordination polymers to increase the adsorption of H-2. Ab initio calculations were performed to investigate the H-2-adsorption capabilities of organic ligands. The adsorption energy of a pyrazine-carboxylate ligand (2.4 kcal/mol), relevant to a coordination polymer with a pillared layer structure, was found to be larger than that obtained by van der Waals interactions alone. An ab initio energy decomposition analysis showed that the stabilization arose mainly from the electronic polarization of H2. We therefore propose a concept of "charge-polarized spaces" to promote polarization. Under the dipolar electric field created by ideal charge-polarized spaces, the adsorption energy markedly increased to 5-8 kcal/cool, which is in the ideal energy range for H-2 adsorption in storage materials. Charge-neutral ligands can also provide electrostatically polarized spaces. Although the binding energy decreases to around 2 kcal/mol, the H-2 polarization effect still increases the adsorption energy. The charge-polarized and electrostatically polarized spaces are therefore an important direction for molecular design of H-2 storage materials.

DOI： 10.1021/cm802566z

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER INST PHYSICS  

The Schrodinger equations for the hydrogen molecular ion (H-2(+)) and its isotopomers (D-2(+), T-2(+), HD+, HT+, and DT+) were solved very accurately using the free iterative complement interaction method, whih is referred to in short as the free complement (FC) method, in the non-Born-Oppenheimer (non-BO) level, i.e., in the nonrelativistic limit. Appropriate complement functions for both electron and nuclei were generated automatically by the FC procedure with the use of the non-BO Hamiltonian, which contains both electron and nuclear operators on an equal footing. Quite accurate results were obtained not only for the ground state but also for the vibronic excited states. For example, we obtained the ground-state energy of H-2(+) as -0.597 139 063 123 405 074 834 134 096 025 974 142 a.u., which is variationally the best in literature. The difference in the nuclear spin states of S-1 (para) and P-3 (ortho) of H-2(+) and some physical expectation values for several of the isotopomers shown above were also examined. The present study is the first application of the FC method to molecular systems with the non-BO Hamiltonian. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3048986]

DOI： 10.1063/1.3048986

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER INST PHYSICS  

Very accurate variational calculations with the free iterative-complement- interaction (ICI) method for solving the Schrodinger equation were performed for the 1sNs singlet and triplet excited states of helium atom up to N=24. This is the first extensive applications of the free ICI method to the calculations of excited states to very high levels. We performed the calculations with the fixed-nucleus Hamiltonian and moving-nucleus Hamiltonian. The latter case is the Schrodinger equation for the electron-nuclear Hamiltonian and includes the quantum effect of nuclear motion. This solution corresponds to the nonrelativistic limit and reproduced the experimental values up to five decimal figures. The small differences from the experimental values are not at all the theoretical errors but represent the physical effects that are not included in the present calculations, such as relativistic effect, quantum electrodynamic effect, and even the experimental errors. The present calculations constitute a small step toward the accurately predictive quantum chemistry. (C) 2008 American Institute of Physics.

DOI： 10.1063/1.2904871

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