The initial photochemical process of triosmiumdodecacarbonyl adsorbed on the surface of silica as studied by picosecond diffuse reflectance laser photolysis and matrix isolation

Abstract

The transient absorption spectrum of the coordinatively unsaturated trinuclear osmium carbonyl cluster Os 3(CO) 11 adsorbed on the surface of silica was observed for the first time by the ps time-resolved diffuse reflectance laser photolysis of Os 3(CO) 12. The present results demonstrated that Os 3(CO) 11 is the photoprimary product responsible for the net oxidative addition of surface hydroxyls to Os 3(CO) 12 adsorbed on the surface of silica to form the surface attached trinuclear species HOs 3(CO) 10-OSi. It was revealed that the addition of surface hydroxyls to Os 3(CO) 11 is completed within the time of our instrumental response (⩽35 ps), which is comparable to the coordination of solvent to coordinatively unsaturated metal carbonyls.