Synthesis, properties and crystal structures of [MoVL(O)l2]PF6′[MoIVL(O)l2], [MoVL(O)(OMe)2]PF6′[MoVILO2(OMe)]BPh4 and [Mo2L2O3(µ-O)l][BPh4]2(L = 1,4,7-trimethyl-1,4,7-triazacyclononane)

A series of mononuclear oxomolybdenum-(IV), -(V) and -(VI) complexes has been prepared from the precursor complex [MoVL(O)l2]PF62 where L = 1,4,7-triazacyclononane. Compound 2 is reduced by NEt3 in MeCN yielding [MoIVl(o)l2]3. The iodide ligands in 2 may be substituted by alkoxy ligands generating paramagnetic mononuclear complexes [MoVL(O)(OMe)l]PF64 and [MoVL(O)-(OMe)2]PF65. The latter is oxidized by H2O2to [MoVILO2(OMe)]BPh46. Complex 2 was found to form the dinuclear diamagnetic species [MoV2L2O2(µ-O)l2][PF6]27 which generates the asymmetric, diamagnetic mixed-valence complex [l(O)LMoIV(µ-O)MoVILO2]BPh48 in the presence of NaOH. Complex 8 undergoes a reversible one-electron-transfer oxidation and paramagnetic [l(O)LMoV(µ-O)MoVILO2]-[BPh4]29 has been isolated. The electrochemical, magnetic, and eletcronic structural as well as infrared and ESR spectral properties of new complexes have been investigated. The structures of 2, 3, 5, 6 and 9 have been determined by X-ray crystallography.