The physical and electronic structure of M2 quadruply bonded complexes:: A density functional theory study

The electronic structures and the physical properties (vertical excitation energies, vibrational stretching frequencies, and bond lengths) of a variety of M-M quadruply bonded (M = Mo, W) complexes are investigated using density functional theory (DFT). By utilizing a variety of pure and hybrid exchange-correlation (XC) functionals and a number basis sets, we are able to recommend a theoretical methodology for most efficiently probing the electronic structures of homoleptic M-2(O2CR)(4) and bridged M-2(O2C-X-CO2)M-2 (R = organic group, typically H; X = conjugated organic group) complexes.