Relative stability of isomers of polynuclear complexes of molybdenum oxides

Abstract

Molybdenum(VI) oxide MoO3 has been studied and the composition of polynuclear molybdenum oxides in the gas phase MoxO3x − y (x = 1–6, y = 0–2) has been determined by laser desorption/ionization time-of-flight mass spectrometry. Quantum-chemical calculations of bond energies, interatomic distances, charge distributions, and molybdenum-molybdenum bond orders for the isomers of neutral polynuclear molecular compounds MoxO3x − y have been performed with the use of the PBE functional with a relativistically corrected potential implemented as the PRIRODA program package. On the basis of the bond energies, the relative stability of the isomers has been estimated. For the MoxOy isomers (x ≥ 3), cyclic structures have been predicted to be more favorable. For the predicted most stable isomers of each MoxOy composition, the bond energies of their positive and negative ions have been calculated. The positive ionization of MoxOy leads to a considerable decrease in the bond energy of the isomer and the negative ionization, to its increase by about 0.1 au.