Synthesis and physicochemical studies of a new molybdenum (IV)-pterin complex undergoing reaction with trimethylamine N-oxide

Abstract

A new compound, [MoIVL₂].3CH₃OH (2), has been synthesized using a redox reaction between Na₂MoO₄.2H₂O and 2-pivaloylamino-6-phenacyl-isoxanthopterin, and characterized by elemental analysis, electrospray ionization mass spectrometry, various spectroscopic methods and cyclic voltammetry. Its optimized geometry (with lowest steric energy) has been obtained by molecular mechanics method; the optimized bond lengths and bond angles data tally with the literature X-ray structural data. Both the kinetic and stoichiometric aspects of its reaction with Me₃N→O have been studied. The negative ΔS# (J K⁻¹ mol⁻¹) value (-282.8) is consistent with an associative mechanism for this process. The product of this reaction has been isolated and characterized to be a μ-oxo binuclear Mo(V) complex, indicating oxygen atom transfer nature of this reaction. ¹H-NMR, fluorescence spectra and CV data indicate the redox “non-innocent” behavior of the pterin ligand in the present case.