Photochemical studies as a function of solvent viscosity. A new photochemical pathway in the reaction of (η5-C5H4Me)2Mo2(CO)6 with CCl4†
Abstract
This paper reports the results of a study that used systematic changes in the solvent viscosity to probe the photochemical reactivity of the Cp′2Mo2(CO)6 (Cp′ = η5-C5H4CH3) molecule. The quantum yields for photolysis of Cp′2Mo2(CO)6 in the presence of CCl4 were studied as a function of solvent viscosity. The quantum yields did not decrease to zero with increasing solvent viscosity but rather leveled off at a constant, non-zero value. This result cannot be explained by any of the previously reported radical or Mo–CO dissociation photochemical pathways for this molecule, and therefore an additional photochemical pathway is suggested to be operating in the reaction. The new pathway may involve a reactive isomer of Cp′2Mo2(CO)6 or possibly electron transfer between the excited state of Cp′2Mo2(CO)6 and CCl4.