| Recently, many coordination compounds with special performances and various structures have been of great interests due to their potential applications as optical materials, superconductor, magnetic, ion exchange, separation and catalyst. Polyoxometalates (POMs) have been attracted extensive attention for many years owing to their interesting structural diversity and various potential applications in different areas such as catalysis, sorption, electrical conductivity, magnetism, photochemistry, medicine and material science. More and more researchers and groups focus their attentions on decorating and fine-tuning POMs at molecular level by capping and supporting them in order to explore their performances and various potential applications. In this paper, the hydroxylpolycarboxylic acids (citric acid, malic acid and tartaric acid) and N-heterocyclic organic ligands have been employed to act as building blocks, and six coordination compounds (1?6)have been got; we also synthesis two POMs (7,8)under hydrothermal condition. Among them, the structures of compound 1,2,4, 6,7 are novel. On the bases of X-ray structural analyses, some compounds have been characterized by IR, XPS, EPR and fluorescence spectra. The thermal analyses and magnetic properties of some compounds have also been studied, which would take a role in the explorations of structures and functions for the compounds.1,We choose transition metal-citric acid-4,4'?bpy as starting materials and obtained three coordination compounds(1?3) under hydrothermal condition: In Ni2(H2cit)2(4,4'bpy) (1), the wave chains which is constructed by citric acid ligands and Ni2+ are connected with 4,4'-bpy to form a 2D structure, and the coordination mode of citric acid is novel; Zn4(cit)2(4,4'-bpy)2(H2O)2-3H2O(2) is 3D structure which is constructed by citric acid and 4,4'?bpy, and the citric acid in 2 exhibits novel coordination modes; Co3(Hcit)2(4,4'-bpy)4(2H2O)-4H2O(3) is 3D structure, but unfortunately, it has been reported before.2,Two coordination compounds have been synthesized in d10 metal?malic acid-N-heterocyclic organic ligands reaction system. Zn(C4H4O5)(4,4'-bpy)-2H2O(4) displays two-dimensional network constructed by malic ligand, 4,4'?bpy acts as terminal ligand alternatively extrude out two sides of the 2-D sheet which is containing a tetramer water cluster. For Cd(C4H2O4)(2,2'-bpy)-H2O(5), the fumarate, which is obtained from the in situ dehydration reaction of malic acid, links Cd atoms to form 1?D zigzag chain with 2,2'?bpy extruding out of one side of the chain as terminal ligand, the structure of 5 has been reported before by fumarate as the starting material.3,[Zn2(C4H4O6)2(4H2O)]2-12H2O (6) has been obtained at room temperature, which is contained two dinuclear compounds and twelve lattice water molecular. The two planes of the two dinuclear compounds are vertical approximately, and water molecular distributes around them.4,We try to synthesis some coordination compounds building with POMs, but a tri-capped mono-supporting Keggin structure tungstovanadophosphate{PW5VW4VIV3IVO40(VIVO)3[Cu(en)2]}[Cu(phen)2]3·4H2O(7) and a vanadium cluster (H3N(CH2)2NH3) [V4O10] (8)were obtained. They both can be further linked to form three-dimensional supramolecular networks through extensive hydrogen bonding. |
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