Date of Award
1989
Degree Type
Dissertation
Degree Name
Doctor of Philosophy
Abstract
This thesis examines the reactivity of the coordinatively unsaturated triplatinum cluster (Pt{dollar}\sb3(\mu\sb3{dollar}-CO)({dollar}\mu{dollar}-dppm){dollar}\sb3{dollar}) (PF{dollar}\sb6{dollar}) {dollar}\sb2{dollar}. This complex can act as a model for a triangle of Pt atoms on a Pt(111) surface and this thesis describes studies of its reactivity towards various main group reagents.;Hydrogen sulphide yielded the cation (Pt{dollar}\sb3{dollar}(H)({dollar}\mu\sb3{dollar}-S) ({dollar}\mu{dollar}-dppm){dollar}\sb3{dollar}) {dollar}\sp+{dollar}, which was characterized crystallographically. In addition, the reaction of H{dollar}\sb2{dollar}S with the analogous palladium species (Pd{dollar}\sb3{dollar}({dollar}\mu\sb3{dollar}-CO)({dollar}\mu{dollar}-dppm){dollar}\sb3{dollar}) (PF{dollar}\sb6{dollar}) {dollar}\sb2{dollar} was also examined. Isolobal substitution of the hydride of the platinum sulphido cluster with a triphenylphosphino gold cation yielded (Pt{dollar}\sb3{dollar}(AuPPh{dollar}\sb3{dollar})({dollar}\mu\sb3{dollar}-S)({dollar}\mu\sb3{dollar}-AgCl) ({dollar}\mu{dollar}-dppm){dollar}\sb3{dollar}) (PF{dollar}\sb6{dollar}) which incorporated a neutral AgCl ligand into the cluster framework. The generality of this reaction was shown by isolation of a similar Pt{dollar}\sb3{dollar}AuAg cluster from (Pt{dollar}\sb3{dollar}(H)({dollar}\mu\sb3{dollar}-SMe)({dollar}\mu{dollar}-dppm){dollar}\sb3{dollar}) (PF{dollar}\sb6{dollar}) {dollar}\sb2{dollar}.;The reaction pathway was elucidated by studying reactions of the triplatinum cluster with various thiols (RSH). The products from the reaction were either (Pt{dollar}\sb3{dollar}(H)({dollar}\mu\sb3{dollar}-SR)({dollar}\mu{dollar}-dppm){dollar}\sb3{dollar}) {dollar}\sp{lcub}2+{rcub}{dollar} or (Pt{dollar}\sb3{dollar}(SR)({dollar}\mu\sb3{dollar}-SR)({dollar}\mu{dollar}-dppm){dollar}\sb3{dollar}) {dollar}\sp{lcub}2+{rcub}{dollar}, depending on the thiol. Alkyl thiols gave solely the former product but aryl thiols yielded both species. Intermediate complexes of RSH could be detected in some cases by low temperature NMR.;Other sulphur reagents, such as CS{dollar}\sb2{dollar}, OCS and KSCN were also examined with regards to the triplatinum and the tripalladium complexes. The products were characterized spectroscopically. Two different mechanisms of reaction were deduced using the kinetic data obtained.;The triplatinum cluster was also reacted with group 14 and group 15 reagents. The triplatinum species reacted with tin(II) species to give tin units capping either one or both faces of the three platinum centers. In addition, the first example of a SnF{dollar}\sb3{dollar} ligand bound to a metal center was characterized by X-ray crystallography. The unsaturated species CCH{dollar}\sp-{dollar} attacked the methylene carbon of the dppm ligand giving a {dollar}\mu\sb2{dollar}-{dollar}\eta\sp3{dollar}-PH{dollar}\sb2{dollar}PCH(CHCH)PPh{dollar}\sb2{dollar} ligand. The cluster containing this novel unit was characterized crtystallographically.;Phenyl phosphine reacted with (Pt{dollar}\sb3{dollar}({dollar}\mu\sb3{dollar}-CO)({dollar}\mu{dollar}-dppm){dollar}\sb3{dollar}) {dollar}\sp{lcub}2+{rcub}{dollar} giving a number of intermediates characterized by multinuclear NMR data. Also, the reactivity of the final, stable product obtained, (Pt{dollar}\sb3{dollar}(OH)({dollar}\mu\sb3{dollar}-PPh)({dollar}\mu{dollar}-dppm){dollar}\sb3{dollar}) {dollar}\sp+{dollar}, toward various one and two electron donors was examined.;Finally a tetraplatinum cluster was also examined, (Pt{dollar}\sb4{dollar}({dollar}\mu{dollar}-H)({dollar}\mu{dollar}-CO){dollar}\sb2(\mu{dollar}-dppm){dollar}\sb3(\eta\sp1{dollar}-dppm)) {dollar}\sp+{dollar}. The fluxionality of this cluster, which differs from that of the usual tetraplatinum butterfly fluxionality, was deduced using multinuclear NMR data. Also its reactivity towards various reagents was examined.
Recommended Citation
Jennings, Michael Craig, "Reactivity Of A Triplatinum Cluster" (1989). Digitized Theses. 1783.
https://ir.lib.uwo.ca/digitizedtheses/1783