Synthesis, spectral, thermal and electrochemical studies of oxomolybdenum(V) and dioxomolybdenum(VI) complexes of an azo dye derived from 4-amino-2,3-dimethyl-1-phenyl pyrazol-5-one

1787-1792Some novel complexes of oxomolybdenum(V) and dioxomolybdenum(VI) with an azodye derived from 4-amino-antipyrine and 3-methoxyphenol have been synthesised and characterized by elemental analyses, molar conductance values, magnetic susceptibility measurements, IR, electronic, ESR, and ¹H NMR spectra and cyclic voltammetric studies. The physico-chemical studies and spectral data indicate that the ligand acts as neutral bidentate. All the complexes are found to be monomeric and neutral with distorted octahedral geometry. The X-ray diffraction studies of [MoO(MOPAAP)Cl₃] and [MoO₂(MOPAAP)Cl₂] indicate that the complexes are orthorhombic with the unit cell dimensions a = 7.3277 Å, b = 9.6663Å and c = 15.8897 Å; and a = 8.5534 Å, b = 9.5986 Å, c = 15.4056 Å respectively.. The CV profile of the complex [MoO(MOPAAP)Cl₃] shows a quasireversible peak, which indicates that the metal-ligand linkage is more covalent in nature. The thermal stabilities of the complexes have been compared and show that [MoO(MOPAAP)Cl₃] is more stable than [MoO₂(MOPAAP)Cl₂]