Ligand Effects on the δ → δ* Band Energies and Intensities in a Series of Diimine Complexes of Dimolybdenum
The complexes Mo2X4(diimine)2 (X = Cl, Br, I and diimine = 2,2′-bipyridine, 4,4′-dimethyl-2,2′-bipyridine, 2,2′-bipyrazine, 3,3′-bipyridazine, 2,2′-bipyrimidine, 1,10-phenanthroline and 4,7-diphenyl-1,10-phenanthroline) have been prepared by reaction of Mo2 (OAc)4with (CH3)3SiX in the presence of excess diimine. The product complexes apparently contain non-bridged quadruple molybdenum—molybdenum bonds. Each molybdenum is coordinated to a bidentate diimine and two halogen atoms. Electronic absorption and electrochemical studies have shown that shifts in the energy of the δ → δ* band are affected by the mixing of this transition with a metal-to-ligand charge transfer transition, probably a δ → π* transition. It was also found that the compounds Mo2X4(diimine)2 react slowly with oxygen to form Mo2O4Cl4(diimine)2 and then MoO2Cl2(diimine). The crystal and molecular structure of MoO2Cl2(4,4′-dimethyl-2,2′bipyridine), determined by a three-dimensional X-ray diffraction study, is reported.
Baird, Donald M.; Yang, F. L.; Kavanaugh, D. J.; Finness, G.; and Dunbar, K. R., "Ligand Effects on the δ → δ* Band Energies and Intensities in a Series of Diimine Complexes of Dimolybdenum" (1996). Chemistry and Physics Faculty Articles. 8.