| This thesis describes investigations into a variety of thermal and photochemical reactions of organoplatinum complexes.;The photochemically induced reductive elimination reactions of the complexes {Pt(,2)H(,3-n)Me(,n)((mu)-dppm)(,2)}('+), (n = 0,1,2,3), were also studied. The reactions were found to involve initial reductive elimination of H(,2)(n = 0,1), CH(,4)(n = 2) and C(,2)H(,6)(n = 3) followed by trapping by solvent, S, giving rise to the platinum containing products {Pt(,2)HS((mu)-dppm)(,2)}('+) (n = 0) and {Pt(,2)MeS((mu)-dppm)(,2)}('+) (n = 1,2,3).;The photochemically induced (beta)-elimination reactions from {Pt(,2)Et(,3)((mu)-dppm)(,2)}('+) and {Pt(,2)Et(dppm)((mu)-dppm)(,2)}('+) were also studied. In each case ethylene was eliminated. The observed chemistry of each was consistent with the primary photochemical step being loss of the Pt-Pt bond. The thermally induced (beta)-elimination reaction of {Pt(,2)Et(dppm)((mu)-dppm)(,2)}('+) was also studied. The reaction followed first order kinetics and the rate was independent of deuterium substitution of the ethyl group, or of added free dppm.;The mechanism of photochemically induced oxidative addition of isopropyl iodide to {PtMe(,2)(phen)} (phen = 1,10-phenanthroline) was investigated. The reaction was found to occur by a free radical chain mechanism, initiated by a ('3)(d(--->)(pi)*) excited state of the platinum complex. The overall mechanism and the associated rate constants have been determined.;The mechanism and energetics of the reaction of tertiary phosphine ligands, L, with {Pt(,2)H(,n)Me(,3-n)((mu)-dppm)(,2)}('+), (n = 2,1) (dppm = bis(diphenylphosphino)methane), have been determined. The reaction was found to occur through coordination of L followed by reductive elimination. In each case H(,2) was found to be eliminated and the platinum(I) products formed were {Pt(,2)HL((mu)-dppm)(,2)}('+) and {Pt(,2)MeL((mu)-dppm)(,2)}('+). The rate constants and equilibrium constants were determined at a variety of temperatures, allowing construction of a reaction coordinate energy level diagram.;A study of the catalysis of the water gas shift reaction by {Pt(,2)H(,2)((mu)-H)((mu)-dppm)(,2)}('+) is also described. |
