| This thesis is largely concerned with the flash and continuous photolysis investigation of the rhodium and iridium phosphine complexes RhCl(CO)(PPh(,3))(,2), RhCl(PPh(,3))(,3), IrCl(CO)(PPh(,3))(,2), H(,2)IrCl(CO)(PPh(,3))(,2), HIrCl(CO)(PPh(,2)C(,6)H(,4))(PPh(,3)), and IrCl(N(,2))(PPh(,3))(,2). Also included is the summary of the flash photolysis of Ru(,3)(CO)(,12). The flash photolysis of RhCl(CO)(PPh(,3))(,2) has afforded the first direct measurements of the rate constants associated with the catalytic intermediate RhCl(PPh(,3))(,2). The rate constants were determined for the addition of CO, PPh(,3), ethene, and H(,2). The chemistry of the Ir analogue of the Wilkinson's catalysis intermediate, IrCl(PPh(,3))(,2), was elucidated from the flash photolysis of IrCl(CO)(PPh(,3))(,2) and IrCl(N(,2))(PPh(,3))(,2). A remarkable observation was that photoreductive elimination of H(,2)IrCl(CO)(PPh(,3))(,2) and HIrCl(CO)(PPh(,2)C(,6)H(,4))(PPh(,3)) generated the same intermediate, IrCl(PPh(,3))(,2). This has indicated that photoreductive elimination of these Ir(III) complexes occur from a pentacoordinate Ir(III) intermediate rather from the parent octahedral complex. Finally, the flash photolysis of Ru(,3)(CO)(,12) has definitively shown that excitation of the Ru cluster results in the formation of "two" distinct intermediates which are respectively precursors of cluster fragmentation and ligand substitution photoproducts. The flash photolysis of Ru(,3)(CO)(,12), (lamda)(,irr) > 400 nm, resulted in an intermediate that gave fragmentation products. The rate of decay of this intermediate was dependent on the electronic nature of the substrate present. The high energy flash photolysis, (lamda)(,irr) > 254 nm, resulted in an intermediate which gave substitution products. The relative rates for addition of substrates to the latter intermediate behind to be Ru(,3)(CO)(,11) were determined to have an order of CO > P(OMe)(,3) > PPh(,3). |
