Based On The Hydrothermal Synthesis And Structural Characterization Of New Hybrid Compounds Polyoxometalate Clusters

In this paper, five novel hybrid compounds, [Ni(phen)2][SiMovI 10MoV2O40(VIVO)2](trea)2-2H20 1, {[Co(phen)2]2[Si-MoVI8Mov404o(VIV0)2]} {[Co(phen)2(H20)]2[SiMoVI8MoV404o(VIV0)2]} -3 H202, {[Co(phen)2]2[GeMovl8MoV404o(VIV0)2]} {[Co(phen)2(H2O)]2[G-eMovl8Mov4040(VIVO)2]}-5H20 3, [Cd2(phen)2(betc)( H2O)]n 4, [CuS(4,4'-bipy)]n 5 (phen = l,10'-phenanthroline, trea = triethylamine, 4,4'-bipy = 4,4'-bipyridine, bete = 1,2,4,5-benzenetetracarboxylate) have been hydrot-hermally synthesized and characterized by IR, EPR, XPS, TG and single-crystal X-ray diffraction. Compound 1, 2 and 3 are constructed directly from saturated Keggin polyoxometalates. Furthermore, polyoxom-etalate skeletons in these compounds are fully maintained. Compound 1 consists of one-dimensioinal zig-zag chains, which are constructed from [SiMoVIioMoV2O40(VIVO)2]2~ polyoxoanion clusters covalently binding to {Ni(phen)2} fragments through {VO} groups. Compound 2 and 3 are isostructural. Compound 2 consist of two-dimensional layers and discrete sixteen metal-cluster [Co(phen)2(H2O)]2[SiMoVI8Mov4O4o(VIVO)2]. In the layer, [SiMo8vlMo4VO4o(VlvO)2]4" polyoxoanion, being a tetradenate ligand and providing two oxygen atoms from opposite {VO} groups and the other two oxygen atoms from opposite {MoO} groups, coordinates to four {Co(phen)2} fragments. Compound 2 represents the first example of extended framework structure based on saturated Keggin POMs, in which both the layers and guests are composed of saturated POMs with covalently linked transition metal complex fragments. Compolund 4 exhibits a one-dimensional chain constructed from two nuclear metal units which are bridged through carboxylate groups. In the structure, 1,2,4,5-benzenetetracarboxylate ligand shows interesting coordination modes. Compound 4 exhibits strong fluorescent emission and may be anexcellent candidate for potential photoactive materials. Compound 5 exhibits a two-dimensional (6,3) net, which is constructed from {(282} units and 4,4'-bipy ligands. Furthermore, the two-dimensional nets interlock to form a neutral three-dimensional network.