Radical cage effects. Effect of radical mass and bond energies on cage recombination efficiencies for photochemical cage pair intermediates of [Mo2(CO)6[(η5-C5H4 CH2CH2OSiMe3)2], [Mo2(CO)6(η5-C5H4 Me)] and [W2(CO)6(η5-C5H4 Me)]

Abstract

The cage recombination efficiency of the [(η ⁵ -C ₅ H ₄ Me)(CO) ₃ W ·, ·W(CO) ₃ (η ⁵ -C ₅ H ₄ Me)] radical cage pair in hydrocarbon solvent systems is higher than that of the analogous, but less massive, [(η ⁵ -C ₅ H ₄ Me)(CO) ₃ Mo ·, ·Mo(CO) ₃ (η ⁵ -C ₅ H ₄ Me )] cage pair; the difference is shown to be attributable not to differences in the radical masses but to differences in the metal–metal bond energies or in the spin–orbit coupling.