Photochemical activation of C–H bonds in supercritical fluids: the dramatic effect of dihydrogen on the activation of ethane by [(η5-C5Me5)Ir(CO)2]

Abstract

UV photolysis of [Cp*Ir(CO)₂](Cp*=η⁵-C₅Me₅) in supercritical CO₂(scCO₂) doped with H₂ or C₂H₆ leads to the formation of [Cp*Ir(CO)(H)R](R = H or C₂H₅) identified by IR spectroscopy; [Cp*Ir(CO)(H)(C₂H₅)] can also be generated by UV photolysis of [Cp*Ir(CO)₂] dissolved in supercritical ethane (scC₂H₆) and the efficiency of the reaction is increased greatly by the addition of H₂ at high pressures to the solution.