Two mononuclear molybdenum(VI) oxo complexes with tridentate hydrazone ligands: Synthesis, structures, and thermal stability

A reaction of [MoO2(acac)(2)] (where acac = acetylacetonate) with two hydrazone ligands in methanol yields two mononuclear molybdenum(VI) oxo complexes with the general formula [MoO2L(CH3OH)], where L = L-1=(4-nitrophenoxy)acetic acid [1-(5-chloro-2-hydroxyphenyl)methylidene]hydrazide (H2L1) and L = L-2=4-dimethylaminobenzoic acid [1-(2-hydroxy-3-methoxyphenyl)methylidene]hydrazide (H2L2). The crystal and molecular structures of the complexes are determined by the single crystal X-ray diffraction method. All of the investigated compounds are further characterized by the elemental analysis, FT-IR spectra, and thermogravimetric analysies. Single crystal X-ray structural studies indicate that hydrazone ligands coordinate to MoO2 cores through enolate oxygen, phenolate oxygen, and azomethine nitrogen atoms. The Mo atoms in both complexes are in octahedral coordination.