Binuclear Dioxomolybdenum(VI) Complexes of Flexibly-Bridged Hexadentate Tetraanionic Schiff's Bases Derived from Methylene- or Dithio-bis(salicylaldehyde) and S-Methyldithiocarbazate or S-Benzyldithiocarbazate

Article abstract of DOI:10.1246/bcsj.68.554

The flexibly-bridged hexadentate tetraanionic ligands, LH4 , react with in a 1:2 molar ratio in refluxing methanol to give complexes of the type <(MoO2)2L>.These complexes show an intense ν(Mo=O) band at 924-948 cm^-1 and a broad but strong band at ca. 850 cm^-1 due to weakened ν(Mo=O) as a result of Mo<*>O->Mo interactions.An oligomeric structure, in which each Mo(VI) ion achieves a pseudo-octahedral structure via Mo<*>O->Mo bridging, has been suggested for these complexes. <(MoO2)2L> reacts with monodentate ligands (D) like pyridine, 4-methylpyridine, and dimethylsulfoxide and forms six-coordinated complexes of the type <(MoO2)2L(D)2> which are monomers.Cyclic voltammetry measurements indicate that these Mo^VIO2 complexes are resistant to Mo^IVO reduction.