Linhua Xie

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

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 three-dimensional porous metal-organic framework with the rutile topology constructed from triangular and distorted octahedral building blocks

The solvothermal reaction of zinc acetate dihydrate with 1,3,5-benzenetricarboxylic acid yields a three-dimensional porous metal-organic framework constructed from triangular and distorted octahedral building blocks, the framework of which can be described as a decorated rutile net.

An organic-inorganic hybrid material constructed from a three-dimensional coordination complex cationic framework and entrapped hexadecavanadate clusters

A unique organic-inorganic hybrid compound has been separated under hydrothermal condition, which is constructed from a three-dimensional second metal-organic subunit and entrapped hexadecavanadate clusters.

Reactions of trivacant lone-pair-containing tungstobismutate and electrochemical behaviors of its sandwich-type products

We report the crystal structure of dimeric precursor Na12[(Na(H2O)2)6(α-BiW9O33)2] (1), and the interaction of this precursor with transition metal ions. Interaction of 1 with Cu2+ in neutral medium leads to the formation of a Hervé-type sandwich polyoxoanion [(Cu(H2O))3(α-BiW9O33)2]12− (2) in high yield. Interaction of 1 with M2+ (M = Zn, Ni, Co, Mn) in acidic aqueous medium leads to formation of Krebs-type sandwich polyoxoanions [(M(H2O)3)2(WO)2(β-BiW9O33)2]10− (3–6). Coordination geometry of the M2+ ions, counterions and precursors can affect the structure of products. In our experiments, only the interaction of 1 with Cu2+ forms a trisubstituted sandwich-type product. The method using [α-BiIIIW9O33]9− as starting material is a convenient and effective route for the synthesis of sandwich-type tungstobismutates in high purity and yield. The electrochemical properties of these sandwich-type tungstobismutates in aqueous solution are described.

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

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.

Hydrothermal assembly of pyrite-related framework: (NH4)2{[Ni(H2O)3]2[TeW6O24]}·H2O

A new 3D heteropolyoxotungstate, (NH4)2{[Ni(H2O)3]2[TeW6O24]} · H2O (1), has been isolated from hydrothermal reactions and characterized by elemental analyses, IR spectra and X-ray crystallography. Single-crystal X-ray diffraction analysis reveals that compound 1 possess unusual (3,6)-connected networks constructed from Anderson-type anions [TeW6O24]6− and nickel cations. The compound exhibits pyrite-like topology in which [TeW6O24]6− anions act as 6-connecting sites and nickel cations act as 3-connecting sites. The magnetic properties of 1 are also presented.

Hydrothermal synthesis, crystal structure and fluorescence of a 3D organic–inorganic hybrid coordination network [CuI(4,4′-bipy)]4[ δ -Mo8O26] exhibiting an interesting polymorphism

A new three-dimensional (3D) extended solid [CuI(4,4′-bipy)]4[δ-Mo8O26] (1) built on {Cu(4,4′-bipy)}+ (bipy = bipyridine) and isopolymolybdate anion [δ-Mo8O26]4− has been synthesized and characterized by elemental analysis, IR, TG, X-ray powder diffraction and single-crystal X-ray diffraction analysis. Compound 1 shows six coppers bonded to [δ-Mo8O26]4− to form inorganic planes which are linked by 4,4′-bipy into a 3D network, the first example of [δ-Mo8O26]4− six-connected linkage based on an organic-inorganic coordination polymer. A polymorphism of compound 1 was found which has an identical molecular formula but absolutely different structure. The influence of the synthesis conditions of 1 has been studied. Furthermore, the fluorescence of 1 is reported.

Synthesis and Structure of a Novel Supramolecular Compound [Co(2,2′-bipy) (H2O)4] [trans-1, 4-chdc] and Separation of Isomer of 1, 4-Cyclohexanedicarboxylic Acid

A supramolecular compound, [Co(2,2′-bipy) (H2O)4] [trans-1, 4-chdc] (compound 1) (2,2′-bipy = 2,2′-bipyridine, 1,4-chdcH2 = 1, 4-cyclohexanedicarboxylic acid), was synthesized and characterized by single-crystal X-ray diffraction analysis, IR spectrometry, TG analysis, and elemental analyses. Single-crystal X-ray diffraction analysis revealed that [Co(2,2′-bipy) (H2O)4]2+ units and adjacent 1, 4-chdc2− formed a single layer by hydrogen bonding and electrostatic interactions along the ac-plane, and two symmetry-related single layers interacted with each other by hydrogen bonding, resulting in a double layer, which further formed a 3-D structure by π-π stacking. The most attractive structural feature of compound 1 is that 1, 4-choc2− possesses only trans-conformation although there are both cis- and trans-conformations in the raw material.