Understanding the origin of metal-sulfur vibrations in an oxo-molybdenum dithiolene complex: Relevance to sulfite oxidase

The reduction potential of sulfite oxidase and relevant models is modulated by sulfur donor effective nuclear charge and nonplanarity of the dithiolelne chelate through changes in the S p-Mo d orbital overlap. In sulfite oxidase, this overlap may be dynamic and effectively mediate charge redistribution during atom and electron transfer and Raman spectra show that mixed-mode Mo-S vibrations of the Mo-dithiolene core, consistent with pseudo-o S(sub dithiolene)-Mo d(sub xy) bonding, may control electron transfer reactivity.