Flash Photolysis of Os(CO)5 in Benzene Solution. Detection of Os(CO)4 Benzene by Fast Time‐Resolved IR Spectroscopy

Abstract
The formation and decomposition of the short‐lived species Os(CO)4 · benzene in benzene are best studied by the methods quoted in the title. The generation of Os(CO)4·benzene was achieved by flash photolysis of Os(CO)5 in benzene. On the basis of kinetic findings, a dissociation mechanism with reversible cleavage of benzene is proposed for the decomposition. Os(CO)4 is finally trapped by CO with re‐formation of Os(CO)5 or by Os(CO)5 with formation of Os2(CO)9.–The CO‐stretching vibration pattern of Os(CO)4·benzene is consistent with a C2v‐structure for the Os(CO)4 unit.