[Synthesis and spectral study of three polyoxovanadium clusters].

Three polyoxovanadium clusters, [{Ni(phen)}2 V4O12] x H2O I, [N(CH2CH2)3NH]Na(H2O)6 {K4 (H2O)4 [V10 O28]} (H2O)4 II and [(CH3)4N]6 [V15 O36 Cl] III, have been synthesized under hydrothermal condition. The relationship between their properties and structures were studied by using FTIR, UV-Vis DRS and flurescence. The FTIR showed that the vibrational frequencies of the group are related to the structure of the materials. In UV-Vis DRS spectra of compound I, there are four characteristic wide peaks at 200, 230, 260 and 350 nm corresponding to O(t) --> V, O(mu) --> Ni, O(mu) --> V charge transfer and phen's pi-pi*, respectively. The fluorescence spectra of clusters have been studies. Finally, the quantum chemistry calculation was performed by Gaussian 98 program to explain the structure characteristic of compound I.