Low temperature matrix photochemistry of M2(CO)4(μ-S-t-Bu)2 and [M(CO)2Cl2]1− anions, where M = Rh and Ir

Photolysis of M2(CO)4(μ-S-t-Bu)2, where M = Rh or Ir, in Nujol matrices at ca. 90 K results in simple CO loss to form a tricarbonyl intermediate analogous to that observed for Rh2(CO)4(μ-Cl)2. Photolysis of the anions, [M(CO)2Cl2]1−, where M = Rh or Ir, in inert ionic matrices at ca. 90 K, results in CO-loss to form an intermediate analogous to that formed by Rh(CO)2(i-Pr2HN)Cl. Finally, photolysis of trans-Ir(CO)(PMe3)2Cl in a Nujol matrix at ca. 90 K gives rise to a new species whose carbonyl band is shifted slightly down in energy as has been observed for trans-Rh(CO)(PMe3)2Cl. In all cases the iridium compounds behave similarly to the rhodium species although the photon energy for iridium photochemistry is typically above that of the rhodium compounds.