Showing papers on "Coordination polymer published in 2008"

Dramatic tuning of carbon dioxide uptake via metal substitution in a coordination polymer with cylindrical pores.

Abstract: A series of four isostructural microporous coordination polymers (MCPs) differing in metal composition is demonstrated to exhibit exceptional uptake of CO2 at low pressures and ambient temperature. These conditions are particularly relevant for capture of flue gas from coal-fired power plants. A magnesium-based material is presented that is the highest surface area magnesium MCP yet reported and displays ultrahigh affinity based on heat of adsorption for CO2. This study demonstrates that physisorptive materials can achieve affinities and capacities competitive with amine sorbents while greatly reducing the energy cost associated with regeneration.

A Crystalline Mesoporous Coordination Copolymer with High Microporosity

Abstract: Porous crystals constructed from the assembly of organic linking units with metal ions or metal clusters are proving to be an exciting class of materials with unprecedented properties and high potential for use in applications such as catalysis, gas storage, and separations. The underlying structure obtained from a given secondary building unit (SBU) with a multitopic ligand can be analyzed, at least with hindsight, as belonging to various nets. In some cases this approach has led to well-defined series with preserved topologies whose members vary in metrics or functionalities. At the same time, it is clear that even a single linker with a given metal under the same reaction conditions can give rise to considerable structural diversity, as is illustrated by our recent application of polymer-induced heteronucleation to the discovery of three new phases based on the simple terephthalic acid linker/zinc nitrate system. Perhaps one lesson to be learned is that there is currently no single structure-predicting design scheme but rather sets of empirically derived default behaviors that can often be used to rationalize the outcome of an experiment. In the case of employing two different linkers possessing the same coordinating functionality, experimental data are lacking, and there is no basis for answering even the most basic question of phase composition. In broad terms we can expect two different behaviors in a crystalline mixed-linker coordination polymer. The default behavior for two components combined and allowed to crystallize is segregation; this behavior forms the basis of purification by crystallization. By contrast, the default behavior when monomers of similar reactivity are combined is random copolymerization. Therefore, it is interesting to contemplate whether in a porous crystal in which strong bonds reversibly assemble the framework, copolymerization patterns will dominate or if self-sorting crystallization will prevail. The former would represent an expeditious route to discover new porous solids. To investigate this question we undertook the synthesis of porous crystals based on two organic linkers of different topologies, namely, terephthalic acid (H2BDC) and 1,3,5-tris(4-carboxyphenyl)benzene (H3BTB). H2BDC is the organic linker that, when combined with Zn, yields MOF-5, a stable cubic structure that is the best studied of the metal–organic frameworks. Using H3BTB under essentially identical synthetic conditions affords MOF177. This trigonal framework exhibits exceptional porosity and surface area and boasts the highest reported uptake of hydrogen gas in a physisorptive material. Combining H2BDC with H3BTB, two ligands possessing aryl carboxylic acid coordinating groups, in the presence of zinc nitrate incorporates both components into a completely new type of structure that can be obtained to the exclusion of materials derived from either pure linker. Figure 1 illustrates the porous crystals produced by heating various ratios of H2BDC and H3BTB in the presence of excess Zn(NO3)2·4H2O at 85 8C for 2 days. Three distinct crystalline phases are observed as the mole fraction of H3BTB is increased. At low H3BTB concentrations, only MOF-5 crystals are formed; however, at a mole ratio of 4:1 (H2BDC:H3BTB), a new needle-shaped phase is formed along with MOF-5. Increasing the H3BTB concentration leads to exclusive formation of the needleshaped phase, which according to powder X-ray diffraction (XRD) data is different from MOF-5 and MOF-177 (Figure S4 in the Supporting Information). A further increase of the H3BTB concentration results in MOF-177 forming as well. Finally, at H2BDC:H3BTB mole ratios greater than or equal to 2:3, MOF-177 is the first product to crystallize out of solution. A single-crystal X-ray diffraction study of the needleshaped crystals revealed a structure with one-dimensional hexagonal channels. The product crystallizes in the space group P63m and dramatically differs from the structures derived from the pure linkers. The framework of the material consists of Zn4O clusters linked together by two BDC and four BTB linkers arranged in an octahedral geometry (Figure 2a). Two BDC linkers are adjacent, leaving the other four positions occupied by BTB linkers, and these octahedra assemble into a structure containing both micropores and mesopores. This product is denoted as UMCM-1 (University of Michigan Crystalline Material-1). The micropores are found in cage-like structures constructed from six BDC linkers, five BTB linkers, and nine Zn4O clusters, and with an internal dimension of approximately 1.4 nm@1.7 nm (subtracting the van der Waals radii of the atoms, Figure 2b). Six such microporous cages assemble together in an edgesharing fashion to define the diameter of the mesopore, a 1D hexagonal channel 2.7 nm@ 3.2 nm (measured between pore walls, Figure 2c). When van der Waals radii of the atoms are taken into account, the mesopore is 2.4 nm@ 2.9 nm. Comparison of the bulk powder XRD pattern to that simulated [*] Dr. K. Koh, Dr. A. G. Wong-Foy, Prof. A. J. Matzger Department of Chemistry and the Macromolecular Science and Engineering Program University of Michigan 930 North University Ave, Ann Arbor, MI 48109-1055 (USA) Fax: (+1)734-6715-8853 E-mail: matzger@umich.edu

Growth-controlled formation of porous coordination polymer particles.

Abstract: Diversely shaped porous coordination polymer particles (CPPs) were synthesized by a simple solvothermal reaction of 1,4-benzenedicarboxylic acid (H2BDC) and In(NO3)3·xH2O in DMF. The growth of crystalline CPPs was controlled through a particle growth blocking event involving blocking agent interaction with particular facets of CPPs and simultaneous particle growth interruption in a specific direction. Systematic reactions in the presence of various amounts of pyridine as a blocking agent were conducted to see the controlled CPP formation. Long rod, short rod, lump, and disk-shaped CPPs with hexagonal faces resulted in the presence of none, 1 equiv, 2 equiv, and 25 equiv of pyridine, respectively. The ultimate particle shape produced depends upon the amount of blocking agents used.

Nanochannels of two distinct cross-sections in a porous Al-based coordination polymer

Abstract: A new aluminum naphthalenedicarboxylate Al(OH)(1,4-NDC)·2H2O compound has been synthesized. The crystal structure exhibits a three-dimensional framework composed of infinite chains of corner-sharing octahedral Al(OH)2O4 with 1,4-naphthanedicarboxylate ligands forming two types of channels with squared-shape cross-section. The large channels present a cross-section of 7.7 × 7.7 A2, while the small channels are about 3.0 × 3.0 A2. When water molecules are removed, no structural transformation occurs, generating a robust structure with permanent porosity and remarkable thermal stability. 2D 1H−13C heteronuclear correlation NMR measurements, together with the application of Lee-Goldburg homonuclear decoupling, were applied, for the first time, to porous coordination polymers revealing the spatial relationships between the 1H and 13C spin-active nuclei of the framework. To demonstrate the open pore structure and the easy accessibility of the nanochannels to the gas phase, highly sensitive hyperpolarized (HP) x...

Mixed-ligand coordination polymers from 1,2-bis(1,2,4-triazol-4-yl)ethane and benzene-1,3,5-tricarboxylate: Trinuclear nickel or zinc secondary building units for three-dimensional networks with crystal-to-crystal transformation upon dehydration

Abstract: The hydrothermal reaction of M(NO3)2·6H2O (M = Ni and Zn) with benzene-1,3,5-tricarboxylic acid (H3btc) and 1,2-bis(1,2,4-triazol-4-yl)ethane (btre) produced the mixed-ligand coordination polymers (MOFs) 3∞{[Ni3(µ3-btc)2(µ4-btre)2(µ-H2O)2]·∼22H2O} (1) and 3∞{[Zn3(µ4-btc)2(µ4-btre)(H2O)2]·2H2O} (3). The compounds, characterized by single-crystal X-ray diffraction, X-ray powder diffraction and thermoanalysis feature trinuclear secondary building units (SBU) within the three-dimensional frameworks. The trinuclear nickel unit in 1 exhibits an intra-trimer together with some weak inter-trimer antiferromagnetic coupling with J = −13.88(8) cm−1 from the magnetic susceptibility measurement between 1.9–300 K. The zinc coordination polymer 3 shows a strong fluorescence at 423 nm upon excitation at 323 nm (not seen in the free btre ligand). Compound 3 is thermally robust until 200 °C (ambient pressure) where loss of the water molecules starts. Careful control of the dehydration procedure (freeze-drying) for 1 and (heating to 280 °C) for 3 allowed for a solid-state reaction with single-crystal-to-single-crystal structural transformations in obtaining the largely dehydrated products 3∞{[Ni3(µ2-btc)2(µ4-btre)2(µ-H2O)2(H2O)2]·4H2O} (2) and 3∞{[Zn3(µ6-btc)2(µ4-btre)2]·∼0.67H2O} (4), respectively. In the transformation from 1 to 2 the unit cell volume is reduced to about 60%. The transition from 3 to 4 involves breakage and formation of new Zn–O bonds.

Assembly of the Highest Connectivity Wells-Dawson Polyoxometalate Coordination Polymer: the Use of Organic Ligand Flexibility

Abstract: Through tuning the length of flexible bis(triazole) ligands and different metal ion coordination geometries, four Wells-Dawson polyoxoanion-based hybrid compounds, [Cu6(btp)3(P2W18O62)]·3H2O (1) (btp = 1,3-bis(1,2,4-triazol-1-y1)propane), [Cu6(btb)3((P2W18O62)]·2H2O (2), [Cu3(btb)6(P2W18O62)]·6H2O (btb = 1,4-bis(1,2,4-triazol-1-y1)butane) (3), and [Cu3(btx)5.5((P2W18O62)]·4H2O (btx = 1,6-bis(1,2,4-triazol-1-y1)hexane) (4), were synthesized and structurally characterized. In compound 1, the metal-organic motif exhibits a ladder-like chain, which is further fused by the ennead-dentate [P2W18O62]6− anions to construct a 3D structure. In compound 2, the metal-organic motif exhibits an interesting Cu−btb grid layer, and the ennead-dentate polyoxoanions are sandwiched by two Cu−btb layers to construct a 3D structure. Compound 3 exhibits a (42·62·82) 3D Cu−btb framework with square and hexagonal channels arranged alternately. The hexa-dentate polyoxoanions incorporate only into the hexagonal channels. In compoun...

Self-assembly of organic-inorganic hybrid materials constructed from eight-connected coordination polymer hosts with nanotube channels and polyoxometalate guests as templates.

Abstract: Two polyoxometalate-templated organic–inorganic hybrid porous frameworks, namely, [Cu2(H2O)2(bpp)2Cl][PM12O40]·∼20H2O (for 1, M = W; for 2, M = Mo; bpp = 1,3-bis(4-pyridyl)propane), were self-assembly obtained and structurally determined by elemental analyses, inductively coupled plasma analyses, infrared spectroscopy, and single-crystal X-ray diffraction analyses. Single-crystal X-ray analysis of these crystals revealed that both of the structures are constructed from eight-connected three-dimensional coordination polymer hosts [Cu2(H2O)2(bpp)2Cl]n3n+ and ball-shaped Keggin-type guests [PM12O40]n3n− as templates. The polymer hosts resulted from a bcc-type framework with nanotubes, and the nanotubes can be regarded as a tetra-stranded helix structure. Furthermore, compounds 1 and 2 exhibit photoluminescent properties at ambient temperature, and the compound 2 bulk-modified carbon paste electrode (2-CPE) displays good electrocatalytic activity toward the reduction of nitrite.

Tuning the Dimensionality of the Coordination Polymer Based on Polyoxometalate by Changing the Spacer Length of Ligands

Abstract: Through tuning the spacer length of flexible bis(triazole) ligands, three Keggin anion-based coordination polymers with different dimensionalities, [Cu4(H2O)4(bte)2(HPMoVI10MoV2O40)]·2H2O (1) (bte = 1,2-bis(1,2,4-triazol-1-yl)ethane), [Cu(btb)][Cu2(btb)2(PMo12O40)] (2) (btb = 1,4-bis(1,2,4-triazol-1-y1)butane), and [Cu5(btx)4(PMoVI10MoV2O40)] (3) (btx = 1,6-bis(1,2,4-triazol-1-y1)hexane), were synthesized and structurally characterized. Compound 1 exhibits a ladder-like chain, in which the polyoxometalate (POM) anions act as the “middle rails” of the ladder. The bte ligand with shortest spacer length acts as not only the bridging linker but also the chelator, which terminates the dimensional extension. Compound 2 exhibits a 2D POM-based framework, containing POM/Cu/btb grid-like layers. In compound 3, there exist three sets of (123)(121)2 2D Cu-btx frameworks to generate a 3-fold interpenetrating structure, into which the hexadentate POM anions are inserted to construct a 3D structure. The structural anal...

Monitoring Shape Transformation from Nanowires to Nanocubes and Size-Controlled Formation of Coordination Polymer Particles

Abstract: Infinite coordination polymers in which metal ions or metal clusters are connected bymolecular building blocks consisting of organic molecules or organometallic complexes have received a great deal of attention due to their useful applications in gas storage, catalysis, optics, recognition, and separation. Rationalization of their chemical and physical properties from structural studies is of fundamental interest in the field of coordination polymer materials. Similarly, microand nanostructured materials are essential in many different areas, such as catalysis, optics, biosensing, medical diagnostics, and data storage, and their size, shape, and composition are the key parameters that dictate chemical and physical properties. Recently, a synthetic strategy for the preparation of microand nanoparticles made from infinite coordination polymers has been demonstrated by several groups. This new class of materials promises to advance nanoparticle science into the realm of infinite coordination polymers, and thereby circumvent the nominal composition limitations generally ascribed to nanoparticles. Control of the composition of nanoparticles generated from functionally defined precursors is a promising research area due to the fundamental interest in materials that have practical applications in chemistry, biology, physics, and related interdisciplinary fields. Coordination polymer particles (CPPs) made from functional metalloligand building blocks have been shown to have a high degree of tailorability. The development and application of CPP materials requires an understanding of how the particles are formed, and the ability to control their size and shape. Herein we describe a solvothermal approach for the synthesis of CPPs made from transition-metal ions and metallosalen (salen= N,N’-bis(salicylidene)ethylenediamine) building blocks. We also describe an interesting nanoparticle wire-to-cube morphological transformation, and the utilization of this transformation process to control CPP formation. In a typical synthesis, fluorescent cubic nanoparticles were prepared by the following simple procedure (Scheme 1): carboxy-functionalized salen ligand N,N’-phenylenebis(salicylideneimine)dicarboxylic acid (1, 3 mg) was dissolved in DMSO (1 mL), and the solution was added to DMF (2 mL) containing two equivalents Zn(OAc)2. One equivalent of Zn coordinates to the salen pocket to give Zn-metalated salen (Zn-MS) complex. The other Zn ion acts as a node that connects to the Zn-MS metalloligands through the carboxylate groups to form coordination polymer (Zn-MSZn); when one equivalent Zn is used, the coordination polymer does not form. The resulting solution was heated at 120 8C for 60 min. During this time, formation of particles was observed. The reaction mixture was cooled to room temperature, and the precipitate was collected by centrifugation and washed several times with DMSO and methanol. The resulting particles were found to be stable in organic solvents (methanol, acetone, DMF, DMSO, and nonpolar solvents), water, and in the dried state. The morphology was characterized by field-emission scanning electron microscopy (SEM; Figure 1). The images show cubic particles with an average size of (308 36) nm. Dynamic light scattering (DLS) measurements on a colloidal Scheme 1. Preparation of Zn-MS-Zn coordination polymers as nanowires and their subsequent transformation into nanocubes.

Local structure of CPO-27-Ni metallorganic framework upon dehydration and coordination of NO

Abstract: Coordination polymer Ni2(dhtp)(H2O)2·8H2O is a 3D network that maintains crystallinity and porosity after solvent removal. A mild thermal treatment in high vacuo at 393 K removes not only water phy...

Five d10 3D Metal−Organic Frameworks Constructed From Aromatic Polycarboxylate Acids and Flexible Imidazole-Based Ligands

Abstract: Five new metal−organic frameworks, namely, [Cd(HIDC)(bix)]n (1), [Cd2(BDC)2(mbix)H2O]n (2), [Cd(HBTEC)(H2bix)0.5]n (3), [Cd(BTEC)(H2mbix)]n (4), and [Zn(BTEC)0.5(mbix)]n (5) (H3IDC = imidazole 4,5-dicarboxylic acid, H2BDC = 1,4-benzenedicarboxylate, H4BTEC = 1,2,4,5-benzenetetracarboxylate, bix = 1,4-bis(imidazol-1-ylmethyl)-benzene, and mbix = 1,3-bis(imidazol-1-ylmethyl)-benzene), have been synthesized under hydrothermal conditions by employing mixed ligands of various carboxylic acids with bix (or mbix). Coordination polymer 1 is a 3-fold-interpenetrated diamondoid network. Particularly, in 1 there occur triple-stranded helices based on Cd ions and bix ligands when viewed along b axis. Coordination polymer 2 is a 2D infinite layer framework, which is further interconnected by hydrogen-bond interactions leading to a 3D supramolecular architecture. Both 3 and 4 feature a 3D open framework with protonated bix (or mbix) locating in the channels, and the 3D open frameworks can be rationalized as a zeolite A...

Metal-organic frameworks constructed from 2,4,6-Tris(4-pyridyl)-1,3,5-triazine.

Abstract: Five new metal-organic frameworks based on 2,4,6-tris(4-pyridyl)-1,3,5-triazine (tpt) ligand have been hydrothermally synthesized. Reaction of tpt and AgNO 3 in an acidic solution at 180 degrees C yields {[Ag(Htpt)(NO3)]NO(3).4H2O}n (1).Ag(I) is trigonally coordinated by two pyridyl nitrogen and one nitrato oxygen to form a 1D zigzag chain. Reaction of tpt with CuSO4 affords {[Cu2(tpt)2(SO4)2(H2O)2].4H2O}n (2). Copper(II) is bonded to two pyridyl nitrogen, two sulfato oxygen, and two water oxygen atoms to form an elongated octahedral geometry. Each H2O ligand bridges two copper(II), whereas sulfate bridges copper(II) via micro-1,3 and micro-1,1 fashions. The copper(II)-sulfate-H2O2D layers are linked by bidentate tpt to form a 3D polymeric structure. Reaction of Cu(SO4)2, tpt, and 1,2,4,5-benzenetetracarboxylic acid (H4btec) in the presence of piperidine gives [Cu(tpt)(H2btec)1/2]n (3). Copper(I) is located in a trigonal-pyramidal coordination environment and coordinated by three pyridyl nitrogen of tpt in a plane, whereas a carboxylate oxygen is coordinated to the copper(I) axially. The tpt-Cu forms a layer, and the layers are linked through H 2btec2- to form a 2D double-layered coordination polymer. Replacing CuSO4 with ZnI2 in the synthesis gives {[Zn(tpt)(btec)1/2].H2O}n (4). Zinc(II) is in a distorted tetrahedral geometry and linked through bidentate tpt and exotetradentate btec4- to form a 2D coordination grid. Reaction of tpt with CuCN leads to the assembly of a 3D metal-organic framework [Cu3(CN)3(tpt)]n (5). Copper(I) is trigonally coordinated by one pyridyl nitrogen and two cyanides to form an intriguing honeycomb architecture. Luminescence study shows that 1, 3, 4, and 5 have blue fluorescence, which can be assigned to be ligand-centered emissions. Thermal analysis shows that all of these complexes are quite stable, and especially for 4, the framework is stable up to 430 degrees C.

Achiral and Chiral Coordination Polymers Containing Helical Chains: The Chirality Transfer Between Helical Chains

Abstract: Four achiral two-dimensional (2D) coordination polymers of [M(HIDC)(H2O)(prz)0.5]n (M = Fe, 1; Mn, 2; Cd, 3) and [Co(HIDC)(H2O)(pyz)0.5]n (4), one chiral 2D coordination polymer of [Mn(HIDC)(H2O)]n (5), and one 2D coordination polymer of [Fe(HIDC)(H2O)]n (6) (H3IDC = imidazole-4,5-dicarboxylic acid, prz = piperazine, pyz = pyrazine) were hydrothermally synthesized and characterized by single-crystal X-ray diffraction. In 1–3, the HIDC2− anions alternately bridge the M(II) cations to form a one-dimensional (1D) infinite helical chain of [M(HIDC)]∞ along the 21 axis. The chirality of the original formed helical chain is transferred oppositely to neighboring helical chains through the parallel coordination interactions of prz molecules between two adjacent chains, resulting in an achiral 2D sheet of [M(HIDC)(H2O)(prz)0.5]n, in which the helical chains are packed in an alternating left- and right-handed chirality. A similar achiral 2D coordination polymer of 4 was obtained when pyz was used as a linker. Compo...

Guest-induced modification of a magnetically active ultramicroporous, gismondine-like, copper(II) coordination network.

Abstract: A novel ultramicroporous coordination polymer, namely [Cu(F-pymo)2(H2O)1.25]n (1, F-pymo = 5-fluoropyrimidin-2-olate), has been prepared and structurally characterized. 1 displays a zeolitic gismondine (GIS) topology, with ca. 2.9 A wide helical channels which, in the thermally activated counterpart (1‘), account for a 13% void volume and are responsible for the observed selective solid−gas adsorption properties toward H2, N2, and CO2. At 77 K 1‘ behaves as a molecular sieve, selectively adsorbing H2 over N2, possibly due to size-exclusion reasons. At variance, although CO2 molecules are slightly larger than the pore size, they are readily incorporated by 1‘ at temperatures as high as 433 K. Variable-temperature X-ray powder diffraction (TXRPD) studies, in the temperature range 303−473 K, show that dehydration is reversible and has almost negligible effects on the network. At variance, the uptake of CO2 occurs through a transient phase and channels expansion. While the gas storage capacity of 1‘ is not ve...

Topological Diversity of Coordination Polymers Containing the Rigid Terephthalate and a Flexible N,N'-Type Ligand : Interpenetration, Polyrotaxane, and Polythreading

Abstract: Reactions of zinc(II) or cadmium(II) salts with terephthalic acid (H 2tp) and 1,3-bis(4-pyridyl)propane (bpp) have afforded four coordination polymers at room temperature, [Zn(μ-tp)(μ-bpp)] n ·2 nH 2O ( 1), [Cd 2(μ-tp) 2(μ-bpp) 3] n ·2 nH 2O ( 2), [Cd(μ-tp)(μ-bpp)(H 2O)] n · nH 2O ( 3), and [Cd 2(μ-tp)(μ-bpp) 2(bpp) 2Br 2] n ( 4). Single-crystal X-ray diffraction has revealed interesting topological features for these compounds. In 1, the Zn atoms act as 4-connected nodes bridged by the tp and bpp ligands to give a 3-fold interpenetrated 3D network with a unique 6 6 topology, which is evidently distinct from 4-connected diamondoid networks. 2 represents the first example of a 2-fold interpenetrated coordination polymer, which possesses a 5-connected 3D framework with a unique 6 10 topology constructed from Cd nodes and tp and bpp spacers. 3 manifests a polyrotaxane motif comprised of two interlocked sets of identical sheets, which result in a 2D → 2D polythreaded layer. Parallel mutual polythreading of 2D...

A Novel Coordination Polymer as Positive Electrode Material for Lithium Ion Battery

Abstract: A new coordination polymer based on an aromatic carbonyl ligand is prepared and investigated as a positive active material for lithium ion batteries, namely, [Li2(C6H2O4)] (1). It is synthesized by the dehydration of [Li2(C6H2O4)·2H2O] (2). These compounds are characterized by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), elemental analysis (EA), single crystal X-ray diffraction methods and powder X-ray diffraction (XRD). As positive material, compound 1 has an initial discharge capacity of 176 mAh·g−1 and a columbic efficiency of 93.18% in the first cycle. It might provide a new method for finding new positive-electrode materials in lithium ion batteries.

A Luminescent and magnetic cyano-bridged Tb3+-Mo5+ coordination polymer: toward multifunctional materials.

Abstract: A new cyano-bridged coordination polymer network Tb(H2O)5-[Mo(CN)8] was obtained and characterized. This compound has a two-dimensional layered structure and presents luminescence along with a magnetic transition at low temperature.

Conformation and Molecular Dynamics of Single Polystyrene Chain Confined in Coordination Nanospace

Abstract: Molecules confined in nanospaces will have distinctly different properties to those in the bulk state because of the formation of specific molecular assemblies and conformations. We studied the chain conformation and dynamics of single polystyrene (PSt) chains confined in highly regular one-dimensional nanochannels of a porous coordination polymer [Zn2(bdc)2ted]n (1; bdc = 1,4-benzenedicarboxylate, ted = triethylenediamine). Characterization by two-dimensional (2D) heteronuclear 1H−13C NMR gave a direct demonstration of the nanocomposite formation and the intimacy between the PSt and the pore surfaces of 1. Calorimetric analysis of the composite did not reveal any glass transition of PSt, which illustrates the different nature of the PSt encapsulated in the nanochannels compared with that of bulk PSt. From N2 adsorption measurements, the apparent density of PSt in the nanochannel was estimated to be 0.55 g cm−3, which is much lower than that of bulk PSt. Results of a solid-state 2H NMR study of the compos...

A novel metal-organic network with high thermal stability: nonlinear optical and photoluminescent properties.

Abstract: A novel zinc(II) 4-(5H-tetrazol)benzoic coordination polymer with an in situ generated tetrazole ligand exhibits the gsi (γ-silicon) topology and high thermal stability; this compound possesses second-order nonlinear optical and interesting heat-induced photoluminescent properties.

Fabrication of Two‐Dimensional Polymer Arrays: Template Synthesis of Polypyrrole between Redox‐Active Coordination Nanoslits

Abstract: 1 / 1 Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University Title: Fabrication of Two-Dimensional Polymer Arrays: Template Synthesis of Polypyrrole between Redox-Active Coordination Nanoslits Author: N. Yanai, T. Uemura, M. Ohba, Y. Kadowaki, M. Maesato, M. Takenaka, S. Nishitsuji, H. Hasegawa, and S. Kitagawa Journal: Angew. Chem. Int. Ed., Vol. 47, No. 51, 9883-9886 (2008) Abstract: Oxidative and intercalative polymerization of pyrrole was conducted within the nanoslits of a layered coordination open framework containing redox-active sites. Isolation of polypyrrole from the host framework led to stacked sheet polymer objects whose orientation and morphology are directly related to the original coordination polymer template.

A New “Opened-Cube” (H2O)10 Cluster and Undulated Water Chain in Porous Metal−Organic Frameworks

Abstract: A novel three-dimensional coordination polymer [Cd2(btec)(btb)3](H2O)10 (1) (btb = 1,4-bis(1,2,4-triazol-1-yl)butane; btec = 1,2,4,5-benzenetetracarboxylate) containing an “opened-cube” with an outer edge discrete water decamer and a thick two-dimensional network [Cd2(phth)2(btb)(H2O)3](H2O)4.5 (2) (phth = 1,2-benzenedicarboxylate) containing an undulated water chain have been synthesized and characterized by single crystal X-ray diffraction analysis.

Crystalline-state guest-exchange and gas-adsorption phenomenon for a "soft" supramolecular porous framework stacking by a rigid linear coordination polymer.

Abstract: A 1D rigid, linear coordination polymer, (4,4′-bipyridine)(2-pyridylsulfonate)copper, has been applied for the controlled-assembly of a new porous host that generates 1D channels by an interdigitated packing through the recognition of hydrogen bonding and π-π stacking interactions. The porous structure is architecturally robust when it reversibly uptakes water molecules and exchanges guest small molecules (MeOH, i-PrOH) from solution as determined by single-crystal-to-single-crystal transformation studies. Moreover, the open-channel solid displays irreversible benzene and toluene vapor sorption behaviors attributed to a widening of the channel cross-section that fetters the larger guest molecules, resulting from the dynamic, “soft” supramolecular framework.