Electronic structures of MoWO(y)- and MoWO(y) determined by anion photoelectron spectroscopy and DFT calculations.

The anion photoelectron spectra of MoWO(y)(-) (y=2-5) and density functional theory (DFT) calculations on MoWO(y)(-) and MoWO(y) are reported and compared to previous comparable studies on Mo(2)O(y)(-)/Mo(2)O(y) and W(2)O(y)(-)/W(2)O(y). The property governing the structure of the lowest energy MoWO(y) anion and neutral clusters is the stronger W-O bond relative to the Mo-O bond, which results in the stabilization of structures in which the Mo center is in a much lower oxidation state than the W center. Anion PE spectra show a much larger change in structure between anion and neutral states than what was observed in the pure Mo(2)O(y)(-) and W(2)O(y)(-) spectra. DFT calculations show increased single-metal localization of spin with respect to the pure metal oxide clusters.