Isolation, Characterization and a Study of the Solvolytic Reactions in Non-aqueous Media of some Dioxomolybdenum (VI) Chelates and the Solvolytic Studies in Methanol of a few other Dioxomolybdenum (VI) Complexes with Monoligands

Department of Chemistry, Jadavpur University, Calcutta 700032

Manuscript received 25 January 1974; revised 17 October 1974; accepted 13 January 1975

Two dioxornolybdenum (VI) chelates having the compositions MoO₂(en)CI₂ and MoO₂(Sal₂en. H₂OCI₂[Sal₂en H₂ = N, N'-disalicyl ethylenediimine] are isolated by reacting MoO₂CI₂H₂O with the appropriate ligands in suitable solvents and they have been characterised by i.r., TGA and magnetic susceptibility studies. The former undergoes 'base solvolysis' and the latter 'acid solvolysis' ia methanol as followed by their conductance measurement in the said solvent. Such conductance study reveals that the complexes MoO₂CI₂L₂ (L = pyridine, 4.nitropyridine and quinoline N-oxides; triphenyl phosphide oxide; hexamethyl phosphoramide and dimethyl sul­phoxide) also undergo 'base solvolysis' in methanol but at a very high dilution (^˷10^-4 M) the triphenyl phosphine oxide, quinoline N-oxide and dimethyl sulphoxide complexes probably undergo further decomposition (a maxima in _{\(\sqrt{C}{M}\)} vs. ∆M plots) when the organic ligand nuke­cales leave the inner sphere of coordination and the solvated organic ligands associate with the protons to a marked extent. This observation suggests that the standard free energy change accompanying the transfer of H [∆G\(_o^t\) (H⁺)] from methanol to the methanolated ligand species in these three cases are negative. A probable qualitative theoretical model in the case of the DMSO complexes has also been incorporated.