Author

Khin Than Aye

Date of Award

1992

Degree Type

Dissertation

Degree Name

Doctor of Philosophy

Abstract

This work deals with synthesis, characterization and reaction mechanisms in studies of the oxidative addition of organic compounds to dimethyl(1,10-phenanthroline)-platinum(II), (PtMe{dollar}\sb2{dollar}(NN)). The organic compounds studied include lactones, epoxides, alkylpalladium(IV) complexes, alkyl halides including a coumarin derivative, and diphenyl diselenide and diphenyl disulphide. A particularly detailed study has been made of the oxidative addition of the C-O bonds of a {dollar}\beta{dollar}-lactone and of epoxides.;The oxidative addition of propiolactone to the platinum(II) complex to give a platina(IV)lactone, (PtMe{dollar}\sb2\{lcub}{dollar}CH{dollar}\sb2{dollar}CH{dollar}\sb2{dollar}C(O)O{dollar}\{rcub}{dollar} (NN)), (NN = 2,2{dollar}\sp\prime{dollar}-bipyridine or 1,10-phenanthroline) is reported. The structure is determined by both NMR and X-ray crystallography. The oxidative addition of propiolactone to the platinum(II) complex is deduced to follow an S{dollar}\sb{lcub}\rm N{rcub}{dollar}2 type mechanism.;The oxidative addition of some simple epoxides to the complex (PtMe{dollar}\sb2{dollar}(NN)) in the presence of carbon dioxide is shown to give platinacarbonate complexes. The rate-determining step in the reaction is the oxidative addition of the epoxide to (PtMe{dollar}\sb2{dollar}(NN)) and a dipolar intermediate, (Me{dollar}\sb2{dollar}(NN)Pt{dollar}\sp+{dollar}CH{dollar}\sb2{dollar}CHRO{dollar}\sp-{dollar}), is formed through nucleophilic attack by platinum(II) on the least substituted carbon atom of the epoxide, CH{dollar}\sb2{dollar}CHRO. The rapid insertion of CO{dollar}\sb2{dollar} then occurs to give the stable cyclic metallacarbonate products.;A study of reactivity, selectivity and mechanism in alkyl halide transfer reactions from palladium(IV) to platinum(II) complexes was carried out. Kinetic studies have shown that the major route involves loss of halide from palladium(IV) in a preequilibrium step, followed by S{dollar}\sb{lcub}\rm N{rcub}{dollar}2 attack by (PtMe{dollar}\sb2{dollar}(NN)) on an alkyl group (PdMe{dollar}\sb3{dollar}(NN)) {dollar}\sp+{dollar} or (PdMe{dollar}\sb2{dollar}(CH{dollar}\sb2{dollar}Ph)(NN)) {dollar}\sp+{dollar}.;The oxidative addition reactions of O-O, S-S and Se-Se bonds to (PtMe{dollar}\sb2{dollar}(NN)) to give the corresponding platinum(IV) complexes have also been studied and the products have been characterized by NMR as (PtMe{dollar}\sb2{dollar}(OH){dollar}\sb2{dollar}(NN)) or (PtMe{dollar}\sb2{dollar}(EPh){dollar}\sb2{dollar}(NN)), E = S or Se. The oxidative addition of 4-bromomethyl-7-methoxycoumarin to the dimethylplatinum complex yields a fluorescent platinum(IV) complex and the oxidative addition of allyl chloride and bromoacetyl chloride to (PtMe{dollar}\sb2{dollar}(NN)) are also described briefly. (Abstract shortened by UMI.)

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