Showing papers by "Lin-Hua Xie published in 2009"

Rational design microporous pillared-layer frameworks: syntheses, structures and gas sorption properties

Abstract: The solvothermal reactions of nickel nitrate hexahydrate, aromatic carboxylic acids, and either 4,4′-bipyridine (bipy) or pyrazine (pyz) produced three open-framework compounds, namely, Ni(HBTC)(pyz)·3DMF 2 (BTC = 1,3,5-benzentricarboxylate, DMF = N,N′-dimethylformamide), Ni2(BTEC)(bipy)3·3DMF 3 (BTEC = 1,2,4,5-benzenetetracarboxylate), together with previously reported Ni(HBTC)(bipy)·3DMF 1. Compound 2 is the product when pyz pillars replace bipy pillars in the reaction of 1, and it is a 3D porous network where honeycomb grid layers constructed by Ni-BTC groups are interlinked by pyz pillars. When the BTEC ligand takes the place of BTC ligand in the system, compound 3 is obtained and it is a 3D connectivity with 1D channels where Ni-BTEC chains are interlinked by bipy ligands. The three compounds feature permanent porosity, which was confirmed by N2 adsorption isotherm measurement, and the architectural features of 1–3 can be ascribed to pillared-layer motifs. Furthermore, hydrogen adsorption measured at 77 K for 1 shows an excess uptake of 3.03 wt% at 20 bar. Details of the synthesis conditions, crystal structures and property measurements of each new compound are described.

A one-dimensional organic–inorganic hybrid constructed by saturated Keggin polyoxoanions and [CuI(4,4′-bipy)] n n + chains

Abstract: A one-dimensional (1-D) organic–inorganic hybrid compound {(H3O)[CuI(4,4′-bipy)]3[SiW12O40]} · 1.5H2O (1) has been synthesized from hydrothermal reaction of Keggin polyoxometalate, cupric nitrate and 4,4′-bipyridine (4,4′-bipy). Single crystal X-ray diffraction shows 1-D zigzag chains built up of saturated Keggin polyoxoanions and infinite [CuI(4,4′-bipy)] n n + units. Zipper-like arrangement of adjacent zigzag chains by hydrogen-bonding interactions leads to a 2-D layer and π–π interactions of 4,4′-bipy ligands from adjacent layers further result in the 3-D structure of 1. All Cu atoms in 1 are three-coordinated with “T-type” geometries, indicating they are univalent in the resultant compound. This result has further been confirmed by the absence of signal in the EPR spectrum of 1.

Organic—Inorganic Hybrids Constructed by Anderson-Type Polyoxoanions and Copper Coordination Complexes.

Abstract: Four organic–inorganic hybrid compounds based on Anderson-type polyoxoanions, namely, {[Cu(2,2′-bpy)(H2O)3]2[Cr(OH)6Mo6O18]}{[Cu(2,2′-bpy)(H2O)Cl][Cu(2,2′-bpy)(H2O)(NO3)][Cr(OH)6Mo6O18]}·18H2O (1), [Cu(2,2′-bpy)(H2O)2Cl]{[Cu(2,2′-bpy)(H2O)2][Cr(OH)6Mo6O18]}·4H2O (2), (H3O){[Cu(2,2′-bpy)(H2O)2]2[Cu(2,2′-bpy)(H2O)]2}[Cr(OH)6Mo6O18]3·36H2O (3), and (H3O){[Cu(2,2′-bpy)(H2O)2]2[Cu(2,2′-bpy)(H2O)]2}[Al(OH)6Mo6O18]3·33H2O (4), were isolated by conventional solution method, and crystal structures have been determined by single-crystal X-ray diffraction. Among them, compound 1 displays a discrete supramolecular structure, compound 2 shows a chainlike structure with chloro-copper complexes as counteranions, and compounds 3 and 4 are isomorphic and exhibit unique 3D open frameworks with lattice water molecules residing in the channels. The compounds 3 and 4 represent the first example of 3D organic–inorganic hybrid compounds in the TMs/2,2′-bpy/POMs system. Investigation of the reaction conditions reveals that the geometry and size of the anions together with its coordinating abilities to the metal centers have a decisive influence on both the composition and the dimensionality of the final compounds.