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Switching between the formation/dissociation of rotaxanes is important to control the function of various types of rotaxane-based materials. We have developed a convenient and simple strategy, the so-called “accelerator addition”, to make a static rotaxane dynamic without apparently affecting the chemical structure. As an interlocked molecule that enables tuning of the formation/dissociation speed, a metallorotaxane was quantitatively generated by the complexation of a triptycene-based dumbbell-shaped mononuclear complex, [PdL2]2+ (L=2,3-diaminotriptycene), with 27C9. As a result of the inertness of the Pd2+-based coordination structure, the metallorotaxane was slowly formed (the static state). This rotaxane formation was accelerated 27 times simply by adding Br− as an accelerator (the dynamic state). A similar drastic acceleration was also demonstrated during the dissociation process when Cs+ was added to the metallorotaxane to form the free axle [PdL2]2+ and the 27C9-Cs+ complex.

DOI： 10.1002/anie.202217048

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

Molecular glasses are low-molecular-weight organic compounds that are stable in the amorphous state at room temperature. Herein, we report a state- and water repellency-controllable molecular glass by n-alkane guest vapors. We observed that a macrocyclic host compound pillar[5]arene with the C2F5 fluoroalkyl groups changes from the crystalline to the amorphous state (molecular glass) by heating above its melting point and then cooling to room temperature. The pillar[5]arene molecular glass shows reversible transitions between amorphous and crystalline states by uptake and release of the n-alkane guest vapors, respectively. Furthermore, the n-alkane guest vapor-induced reversible changes in the water contact angle were also observed: water contact angles increased and then reverted back to the original state by the uptake and release of the n-alkane guest vapors, respectively, along with the changes in the chemical structure and roughness on the surface of the molecular glass. The water repellency of the molecular glass could be controlled by tuning the uptake ratio of the n-alkane guest vapor.

DOI： 10.1039/d2sc00828a

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SignificanceWe first observed a transient chirality inversion on a simple unimolecular platform during the racemization of a chiral helical complex [LCo3A6]3+, i.e., the helicity changed from P-rich (right-handed) to M-rich (left-handed), which then racemized to a P/M equimolar mixture in spite of the absence of a reagent that could induce the M helix. This transient chirality inversion was observed only in the forward reaction, whereas the reverse reaction showed a simple monotonic change with an induction time. Consequently, the M helicity appeared only in the forward reaction. These forward and reverse reactions constitute a hysteretic cycle. Compounds showing such unique time responses would be useful for developing time-programmable switchable materials that can control the physical/chemical properties in a time-dependent manner.

DOI： 10.1073/pnas.2113237119

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

A convenient method for the synthesis of pentaarylcyclobutenylrhodium(I) complexes from [Rh(cod)OH](2), arylboronic acids, and diphenylacetylene derivatives is presented. The present rhodium(I) complexes provided insights into the mechanism for the formation of highly reactive living polymerization catalysts from [Rh(nbd)Cl](2), by an analogous method, which was previously developed by us. In addition, the complex showed high reactivity as a catalyst for the polymerization of sodium propiolate.

DOI： 10.1021/acs.organomet.1c00712

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

New amphiphilic chiral salen complexes having hydrophilic triethyleneglycol chains and a hydrophobic π-extended metallosalen core formed monolayers at the air–water interface, which showed unique conformational changes upon mechanical compression.

DOI： 10.1039/d2dt03201e

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The reaction of calix[4]arene derivatives 1a and 1b bearing four salicylaldehyde moieties with 1,3-propanediamine gave macro-cyclic trimers 5a and 5b, respectively, which have intramolecular bridges formed via the flattened cone conformation. In contrast, a capsular-shaped dimeric cage [7a.2Na](2+) was selectively formed when the conformation of the calix[4]arene moiety of la was fixed in the spread cone conformation by complexation with Na+ at the lower-rim amide groups.

DOI： 10.1039/d1cc05553d

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

Unique bench-stable rhodium(I) complexes bearing an aryl-substituted 1,3,5-hexatriene chain have been synthesized by reactions of (bicyclo[2.2.1]hepta-2,5-diene)rhodium(I) chloride dimer ([Rh(nbd)Cl](2)) with aryl boronic acids and diphenylacetylenes in the presence of a 50 % aqueous solution of KOH. X-ray crystallographic analysis of the isolated complexes indicated a square-planar structure stabilized by a strong interaction with one of the aryl groups on the 1,3,5-hexatriene chain, which has a helical structure. The helical chirality of the isolated rhodium complexes was confirmed to be sufficiently stable to be resolved into enantiomers by HPLC on a chiral stationary phase at room temperature. It was confirmed that the isolated rhodium complexes functioned as initiators for living polymerization of phenylacetylene to give cis-stereoregular poly(phenylacetylene) with a well-controlled molecular weight.

DOI： 10.1002/anie.202108032

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Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1002/anie.202108032

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Japan Society for Analytical Chemistry  

The structure of the dinuclear Co(II, III) mixed-valence complex [(CoCoIII)-Co-II(tpdb)(CH3CO2)(CH3O)](ClO4)(2)center dot 0.75CH(3)OH center dot 0.25CH(3)CN (1) was determined by X-ray crystallography, where tpdb is N,N,N',N'-tetrakis(2-pyridylmethyl)-1,4-diamino-2-butanolate. The compound crystallizes in the monoclinic space group, P2(1)/c, with a = 10.4372(4), b = 27.8578(10), c = 13.5496(5)angstrom, beta = 102.8116(10), Z = 4, V = 3841.6(2)angstrom(3). The R1 [I > 2 sigma(I)] and wR2 (all data) values are 0.0398 and 0.1035, respectively, for all 6799 independent reflections. The complex has a (mu-acetato)bis(mu-alkoxo)-dicobalt(II, III) core structure.

DOI： 10.2116/xraystruct.37.13

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<p>A new chiral receptor based on two salen zinc(<sc>ii</sc>) complex units and a spirobifluorene linker enantioselectively binds chiral carboxylate guests.</p>

DOI： 10.1039/d1dt00218j

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

Host-guest binding behavior of macrocyclic hosts is significantly influenced by the shapes and sizes of the hosts. In particular, closing/opening the apertures of the hosts controls the guest uptake/release. A post-metalation modification method was used to achieve the open/close conversions. The starting open complex, [LCo2(pip)(4)](OTf)(2), was efficiently converted to the closed complex, [LCo2(hda)(2)](OTf)(2), which has a doubly bridged structure. The conversion of this closed complex to the open complex [LCo2(hda)(2)(OAc)](+) was too slow to be completed, but this gate-opening was dramatically accelerated by the addition of Na+. The Na+ binding was also significantly enhanced by the gate-opening, that is, conversion of [LCo2(hda)(2)](2+) to [LCo2(hda)(2)(OAc)](+).

DOI： 10.1002/chem.202004487

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A rational design to create vapoluminescence materials is to install fluorescent tags into molecules. Changing the distance and arrangement of the fluorescent tags can be performed to trigger the vapoluminescence behavior. Herein, we unexpectedly observed a vapoluminescence behavior triggered by a crystal-state host-guest complexation between pillar[6]arene host crystals and organic guest vapors that both exhibit no fluorescence in the visible-light region. After the uptake of the guest vapors, the host-guest complex crystals exhibit blue fluorescence in the visible-light region. Charge-transfer interactions between the host and guest molecules in the crystal state mainly contribute to the observation of fluorescence in the visible-light region.

DOI： 10.1021/acs.cgd.0c00982

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

A novel cooperative [3]pseudorotaxane system consisting of dibenzo-24-crown-8 (DB24C8) and diphenylviologen axle has been developed. The two-step formation of the [3]pseudorotaxane occurred in a positive-cooperative manner. The corresponding [3]rotaxane was successfully obtained from just a stoichiometric mixture of each component by end-capping without dissociation.

DOI： 10.1039/d0cc03131c

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

The structure of the dinuclear Co(II, III) mixed-valence complex [(CoCoIII)-Co-II(bpmp)(C6F5CO2)(2)](ClO4)(2)center dot C2H5OC2H5 (1) was determined by X-ray crystallography, where bpmp is 2,6-bis[bis(2-pyridylmethyl)aminomethyl]-4-methylphenolate. The compound crystallizes in the triclinic space group, P (1) over bar, with a = 11.1387(5), b = 11.5941(5), c = 21.7622(9)angstrom, alpha = 88.1955(13), beta = 76.0524(14), gamma = 79.2320(11)degrees, Z = 2, V = 2679.3(2)angstrom(3). The R1 [I > 2 sigma(I)] and wR2 (all data) values are 0.0370 and 0.1028, respectively, for all 9437 independent reflections. The complex has a (mu-phenoxo)bis(mu-pentafluorobenzoate)dicobalt(II, III) core structure.

DOI： 10.2116/xraystruct.36.23

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DOI： 10.1002/ange.201916515

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

Supramolecular chemistry in confined spaces constructed from macrocyclic molecules has attracted much attention because it can utilize the specific binding properties of macrocyclic cavities. Herein we report the preparation of length-controlled discrete tubular structures by homo-/co-assembly of rim-differentiated and peralkylamino-substituted pillar[5]arenes via hydrogen bonds and salt bridges. By dimerization and trimerization, the expanded tubes show a fivefold helical structure and stepwise binding, respectively. We found that the exchange speed of guest molecules in the tubes could be controlled by varying the tube length.

DOI： 10.1002/anie.201916515

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We propose post-metalation modification as a useful strategy to control the guest recognition behavior of a metal-containing macrocyclic host. This is based on the ligand exchange of the axial ligands of a cobalt(III) dinuclear macrocyclic host, [LCo2X4](2+) (X=axial amine ligand). Four piperidine ligands in [LCo2(pip)(4)](2+) (pip=piperidine) were site-selectively replaced with primary amines. The competitive experiments revealed that the order of the affinity toward the cobalt centers in [LCo2X4](2+) is primary amine > secondary amine > tertiary amine and that the piperidine-coordinating complex, [LCo2(pip)(4)](2+), was reasonably reactive among the isolable complexes. Indeed, two piperidine ligands at the diagonal positions in [LCo2(pip)(4)](2+) were site-selectively replaced with pyridine or acetate ion. The replacement of piperidine with acetate ion significantly enhanced the recognition ability towards Na+.

DOI： 10.1002/chem.202001072

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Language：English   Publisher：CHEMICAL SOC JAPAN  

While host-guest binding is generally a very fast reaction, guest uptake/release sometimes becomes slow particularly when the host cavity is separated from the outside by relatively narrow openings. If the apertures are opened/closed, the host molecule can be used as a nano-sized container just like a capped container in our daily life. This review focuses on the recent development of the kinetic control of guest uptake/release based on the open/close functions, etc., in addition to fundamental kinetic studies of host-guest binding.

DOI： 10.1246/cl.200017

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DOI： 10.1021/acs.inorgchem.9b02587

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DOI： 10.1021/jacs.9b06926

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DOI： 10.1016/j.tetlet.2019.06.057

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DOI： 10.1002/chem.201805799

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Publishing type：Research paper (scientific journal)   Publisher：Wiley  

DOI： 10.1002/chem.201900219

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

Host-guest complexation has been mainly investigated in solution, and it is unclear how guest molecules access the assembled structures of host and dynamics of guest molecules in the crystal state. In this study, we studied the uptake, release, and molecular dynamics of n-hexane vapor in the crystal state of pillar[5]arenes bearing different substituents. Pillar[5]arene bearing 10 ethyl groups yielded a crystal structure of herringbone-type 1:1 complexes with n-hexane, whereas pillar[5]arene with 10 allyl groups formed 1:1 complexes featuring a one-dimensional (1D) channel structure. For pillar[5]arene bearing 10 benzyl groups, one molecule of n-hexane was located in the cavity of pillar[5]arene, and another n-hexane molecule was located outside of the cavity between two pillar[5]arenes. The substituent-dependent differences in molecular arrangement influenced the uptake, release, and molecular dynamics of the n-hexane guest. The substituent effects were not observed in host-guest chemistry in solution, and these features are unique for the crystal state host-guest chemistry of pillar[5]arenes.

DOI： 10.1002/chem.201805733

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DOI： 10.2116/xraystruct.35.5

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

Confinement of polymers in nano-spaces can induce unique molecular dynamics and properties. Here we show molecular weight fractionation by the confinement of single polymer chains of poly(ethylene oxide) (PEO) in the one-dimensional (1D) channels of crystalline pillar[5]arene. Pillar[5]arene crystals are activated by heating under reduced pressure. The activated crystals are immersed in melted PEO, causing the crystals to selectively take up PEO with high mass fraction. The high mass fractionation is caused by the greater number of attractive CH/pi interactions between PEO C-H groups and the pi-electron-rich 1D channel of the pillar[5]arene with increasing PEO chain length. The molecular motion of the confined PEO (PEO chain thickness of similar to 3.7 angstrom) in the 1D channel of pillar[5]arenes (diameter of similar to 4.7 angstrom) is highly restricted compared with that of neat PEO.

DOI： 10.1038/s41467-019-08372-1

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

A triptycene-based shape-persistent belt-shaped macrocycle, metallonanobelt, was synthesized by the self-assembly of 2,3,6,7-tetraaminotriptycene L and square planar Pd2(+). The pentamer was selectively formed by the complexation of L with Pd2(+) in the presence of the pillar[6]arene derivative P6 having triethylene glycol pendant as a template, whereas a mixture of a trimer, tetramer, and pentamer was obtained in the absence of the template. The pentamer was successfully isolated based on the solubility difference between the metallonanobelt and the template. It was also revealed that the isolated pentamer was remarkably stable in solutions such as acetonitrile or methanol thanks to the relatively inert planar chelate metal complex, [Pd(o-phenylenediamine)(2)] unit. Thus, we can handle the metallonanobelt almost as a static organic nanobelt that is synthesized covalently.

DOI： 10.1021/acs.inorgchem.8b02804

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DOI： 10.1021/acs.joc.8b01252

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We report a simple and easy-to-operate method for separating n-alkanes: when we immersed activated pillar[5] arene crystals into a mixture of n-alkanes with various chain lengths, the crystals preferentially took up n-alkanes with longer chain lengths.

DOI： 10.1039/c7cc04454b

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A (mu-peroxo)diiron(III) complex [Fe-2(L-Ph4)(O-2)(Ph3CCO2)](2+) (1-O-2) with a dinucleating ligand (L-Ph4), generated from the reaction of a carboxylate bridged diiron(II) complex [Fe-2(L-Ph4)(Ph3CCO2)](2+) (1) with dioxygen in CH2Cl2, provides a diiron(IV)-oxo species as an active oxidant which is involved in either aromatic ligand hydroxylation or benzyl alcohol oxidation.

DOI： 10.1039/c7cc04382a

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

The switching of molecular recognition selectivity is important for tuning molecular functions based on host-guest binding. While the switching processes in artificial functional molecules are usually driven by changes of the thermodynamic stabilities, non-equilibrium phenomena also play an important role in biological systems. Thus, here we designed a host-guest system utilizing a non-equilibrium kinetically trapped state for on-demand and time-programmable control of molecular functions. We synthesized a bis(saloph) macrocyclic cobalt(III) metallohost 1(OTf)(2), which has anion caps at both sides of the cation-binding site. The anion caps effectively retard the guest uptake/release so that we can easily make a non-equilibrium kinetically trapped state. Indeed, we can obtain a long-lived kinetically trapped state {[1 center dot K](3+) +La3+} prior to the formation of the thermodynamically more stable state {[1 center dot La](5+) +K+}. The guest exchange to the more stable state from this kinetically trapped state is significantly accelerated by exchange of TfO- anion caps by AcO- in an on-demand manner.

DOI： 10.1038/ncomms16005

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Precise modulation of cation binding affinity was accomplished by the efficient two-step conversion of a newly synthesized macrocyclic ligand H4L2 having a 24-crown-8-like cavity and two saloph moieties. The conversion of (HL2)-L-4 into (LNi2)-Ni-2 resulted in a 120-fold enhancement in the binding affinity towards Cs+. The electrochemical reduction of (LNi2)-Ni-2 further enhanced the recognition ability by 3 orders of magnitude.

DOI： 10.1039/c7cc02641b

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

A one-pot synthetic method was developed for multifunctional dihydrooxazole and oxazole derivatives. New reaction sequences were developed involving the formation of isocyanide dichloride, an aldol-type reaction with aldehydes, and a nucleophilic addition elimination reaction, which efficiently afforded the dihydrooxazole and oxazole scaffolds.

DOI： 10.1021/acs.joc.7b00296

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

Colored crystals of pillar[5]arene containing one benzoquinone unit were found to exhibit alkane-shape-selective vapochromic behavior. Activated pillar[5]arene crystals, prepared by removing solvated methanol from pillar[5]arene crystals, changed color from dark brown to light-red after exposure to linear alkane vapors; however, no color changes were observed on exposure to branched or cyclic alkanes. Uptake of methanol vapor by the activated crystals induced a different color change, from dark-brown to black. This multi-vapochromism results from the different intermolecular pi-stacking interactions between the benzoquinone and 1,4-diethoxy-benzene units in the alkane- and methanol-containing crystals. Unlike most known vapochromic materials, these pillar[5]arene-based materials were highly stable; after uptake of n-alkanes or methanol the color of the crystals did not change after storage in air for 3 weeks. This is because the included guests were stabilized in the cavity by multiple CH/pi interactions.

DOI： 10.1021/jacs.7b00631

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：東京化学同人  

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

We have developed a Ugi-type multicomponent reaction, in which a nitrile imine, an isocyanide, and an isocyanate reacted to give the corresponding 1,2,4-triazinedione derivatives in good-to-high yields. This reaction is one of the few examples of isocyanide-based multicomponent reactions using an isocyanate in place of a carboxylic acid. A wide range of nitrile imines, isocyanides, and isocyanates were found to be applicable to the reaction.

DOI： 10.1002/ajoc.201600191

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

(mu-1,2-Peroxo) diiron(III) complexes (2-R) with dinucleating ligands (R-L) generated from the reaction of bis(mu-hydroxo) diiron(II) complexes [Fe-2(R-L)(OH)(2)](2+) (1-R) with dioxygen in acetone at -20 degrees C provide a diiron-centred electrophilic oxidant, presumably diiron(IV)-oxo species, which is involved in aromatic ligand hydroxylation.

DOI： 10.1039/c5dt04088d

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The reaction of (Z)-hydroximoyl chlorides with isocyanides promoted by phosphinic acid in the presence of triethylamine proceeds smoothly to afford alpha-(hydroxyimino)amides in good to high yields. Phosphinic acid plays an important role in effectively promoting the reaction. A wide range of (Z)-hydroximoyl chlorides and isocyanides were found to be suitable for this reaction.

DOI： 10.1039/c5ob02032h

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A newly synthesized dipyrrinone derivative bearing an ethoxycarbonyl group at the pyrrolic-alpha position exhibited solvent-dependent dual-mode photochromism between T-and P-types. While this molecule underwent thermally reversible (T-type) photoresponsive reaction in chloroform, it became a thermally irreversible (P-type) system in methanol.

DOI： 10.1039/c5cc07625k

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

Activated perethylated pillar[5]arene crystals show an unexpected alkane-shape-and -length-selective gate-opening behavior. Activated crystals were obtained upon removing solvents from perethylated pillar[5]arene crystals by heating. The activated crystals could quantitatively take up n-alkanes with carbon chains containing more than five carbon atoms as a consequence of their gate-opening pressure. As the chain length of the n-alkanes increased, the gate pressure decreased. A transformation into a herringbone structure was induced when n-hexane was used as a guest. By contrast, cyclic and branched alkanes were not taken up and could not induce a crystal transformation because they were too large to fit in the cavities of the pillar[5]arene. Alkane-shape-selective molecular recognition of pillar[5]arenes in the solution state was translated into the vapor/crystal state.

DOI： 10.1002/anie.201503489

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DOI： 10.1002/ange.201503489

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

A mononuclear peroxocarbonato-iron(III) complex [Fe-(6Me-pic)(2)(O2C(O)O)](-) (1-O2C(O)O) with bidentate ligands (6Me-pic), prepared by the reaction of a carbonato-iron(III) complex [Fe(6Me-pic)(2)(CO3)(-) (1-CO3) with H2O2, was fully characterized. 1-O2C(O)O showed reversible O-O bond cleavage and reformation of the peroxo group under CO2 at 25 degrees C. 1-O2C(O)O is capable of not only oxidizing the C=C bond of cyclooctene but also the C-H bond of toluene. As for cyclooctene, epoxidation is favorable under CO2 in the presence of H2O, while cis-dihydroxylafion precedes under N-2, indicating that the oxidation reactivity of 1-O2C(O)O toward cyclooctene can be tuned by changing the concentration of CO2 and H2O.

DOI： 10.1246/cl.141058

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

Structural transformability accompanied by molecular accommodation is a distinguished feature of porous coordination polymers (PCPs) among porous materials. Conventional X-ray crystallography allows for the determination of each structural phase emerged during transformation. However, the propagation mechanism of transformation through an entire crystal still remains in question. Here we elucidate the structural nature of the spatial transient state, in which two different but correlated framework structures, an original phase and a deformed phase, simultaneously exist in one crystal. The deformed phase is distinctively generated only at the crystal surface region by introducing large guest molecules, while the remaining part of crystal containing small molecules maintains the original phase. By means of grazing incidence diffraction techniques we determine that the framework is sheared with sharing one edge of the original primitive cubic structure, leading to the formation of crystal domains with four mirror image relationships.

DOI： 10.1021/ja409965g

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Language：English   Publisher：CHEMICAL SOC JAPAN  

Entangled porous coordination frameworks, wherein two or more distinct frameworks are catenated over an entire crystal, are known to demonstrate unique structural flexibilities in response to the accommodation of molecules in the voids between the frameworks. In this highlight review, we introduce key functions of entangled frameworks based on two principles of their dynamic features: shearing and displacement. We further describe strategies to control the flexibilities; one is a molecular chemistry approach to functionalize frameworks by chemical modification, and the other is a mesoscopic chemistry approach to change the physical form, in particular, the crystal size.

DOI： 10.1246/cl.130357

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

Flexible porous coordination polymers change their structure in response to molecular incorporation but recover their original configuration after the guest has been removed. We demonstrated that the crystal downsizing of twofold interpenetrated frameworks of [Cu-2(dicarboxylate)(2)(amine)](n) regulates the structural flexibility and induces a shape-memory effect in the coordination frameworks. In addition to the two structures that contribute to the sorption process (that is, a nonporous closed phase and a guest-included open phase), we isolated an unusual, metastable open dried phase when downsizing the crystals to the mesoscale, and the closed phase was recovered by thermal treatment. Crystal downsizing suppressed the structural mobility and stabilized the open dried phase. The successful isolation of two interconvertible empty phases, the closed phase and the open dried phase, provided switchable sorption properties with or without gate-opening behavior.

DOI： 10.1126/science.1231451

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Hybridized porous coordination polymers (PCPs) are synthesized through epitaxial growth or ligand replacement. Whereas epitaxial growth on the core crystal leads to a sandwich type PCP, ligand replacement near the surface of core crystal results in a core-shell type PCP.

DOI： 10.1039/c3dt50679g

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Nanocrystals of three-dimensional pillared-layer type porous coordination polymers, [Zn-2(ndc)(2)(dabco)](n), were fabricated by microwave-assisted coordination modulation, and its morphology was controlled by changing the modulator concentration. Adsorption measurement supported that the crystallinity and intrinsic porosity were maintained even for nanosized crystals, comparable to the corresponding micrometer-sized bulk powder crystals.

DOI： 10.1246/cl.2012.1436

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Porous coordination polymers (PCPs), with their ordered nanoporous systems and large surface areas, are very attractive for numerous applications that involve controlled molecular transport properties. To fully exploit their potential, a straightforward processing method to deposit the PCP crystals on various substrates and to create freestanding membranes with a controlled pore orientation is highly desirable. Here, we report a strategy to self-assemble PCP crystals into two-dimensional monolayers using Langmuir-Blodgettry. This approach allows the deposition on various substrates over several square centimeters, uniformly and with controllable density of the crystals. In addition we show that by controlling the morphology of the crystalline building blocks we can program their orientation on the substrates. Using a copper grid as the substrate, these assemblies can also be fabricated as freestanding sheets. This approach represents a very simple and scalable processing method to translate the orientation of the channel network from the individual crystal to the macroscopic scale, and can help to incorporate this interesting class of materials within advanced hierarchical systems.

DOI： 10.1039/c2jm16333k

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Spatiospecific functionalisation of a shell crystal was performed in a core-shell crystal of a porous coordination polymer (PCP) via post-synthetic modification (PSM). The shell crystal allowed the core crystal to selectively accumulate N,N-dimethylaniline (DMA) and afford the intense exciplex fluorescence.

DOI： 10.1039/c2cc31421e

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

A series of heteroleptic [Ti1(2)X](-) complexes have been selectively constructed from a mixture of Ti-IV ions, a pyridyl catechol ligand (H(2)1; H(2)1 = 4-(3-pyridyl)catechol), and various bidentate ligands (HX) in the presence of a weak base, in addition to a previously reported [Ti1(2)(acac)](-) (acac = acetylacetonate) complex. Comparative studies of these Ti-IV complexes revealed that [Ti1(2)(trop)](-) (trop = tropolonate) is much more stable than the [Ti1(2)(acac)](-) complex, which allows the replacement of acac with trop on the [Ti1(2)(acac)](-) complex. This Ti-IV-centered site-selective ligand exchange reaction also takes place on a heteronuclear Pd-II-Ti-IV ring complex with the preservation of the Pd-II-centered coordination structures. Intra- and intermolecular linking between two Ti-IV centers with a flexible or a rigid bis-tropolone bridging ligand provided a tetranuclear and an octanuclear Pd-II-Ti-IV complex, respectively. These higher-order structures could be efficiently constructed only through a step-wise synthetic route.

DOI： 10.1002/chem.200903509

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

Heteronuclear, supramolecular ring and cage complexes have been constructed from a pyridyl catechol ligand, TiO(aca)(2), and PdCl(2)(CH(3)CN(2)). These two complexes are quantitatively interconvertible, in which Ti(4+) centered coordination changes take place between a well-known Ti(catecholato)(3) and a newly established TiH(catecholato)(2)(acetylacetonato) structures. The Ti(4+)-centered structural changes arise from the changes in the component fraction basicity condition.

DOI： 10.1021/ja803115j

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