On the basis of 5 crystal and mol. structures of novel dimeric di-m-oxo, di-m-oxo-m-carboxylato and m-oxo-m-SO4 bridged oxomolybdates (V) (QH)4[Mo2O4(NCS)6], H(PyH)3[Mo2O4(C2O4)2(H2O)2]2.2H2O, (QH)3[Mo2O4(C4H3OCOO)(NCS)4], (PyH)3.[Mo2O4(CH3OH(NCS)5] and (PyH)4[Mo2O3SO4(NCSw)6] determine by authors and the data reported in literature, the structural characteristic of oxodimolybdates containing oxo bridges are summarized. The electronic structure and forming mechanism for dimeric cluster was studied by SCC-EHMO method. A normal coordinate anal. on Mo2O42+ and Mo2O3SO42+ core were carried out and the IR spectra were assigned.

Key words: COMPUTER APPLICATIONS, QUANTUM CHEMISTRY, NITROGENASE, MOLYBDENUM COMPLEX, CHEMICAL BONDS, OXYGEN HETEROCYCLICS, CLUSTER COMPOUND, FLUTTER ANALYSIS, DINUCLEAR COMPLEX, BRIDGE COMPOUNDS