Photochemistry of Mn2(CO)10

Abstract Flash photolysis studies on Mn 2 (CO) 10 in cyclohexane and THF show that the dominant photochemistry involves photolytic formation of 2 Mn(CO) 5 followed by recombination at rates near the diffusion-controlled limit. A second, relatively, long-lived intermediate is also observed and earlier observations of photodecomposition and photodisproportionation can be accounted for in terms of secondary photolysis of this intermediate. For the equilibrium: Mn 2 (CO) 10 ⇌ 2 Mn(CO) 5 △H ∼ 36 kcal/mol, △S ∼ 32 e.u., and K (25°C) ∼ 10 − 20 where the thermodynamic values have been estimated from kinetic measurements.