Notes. Exchange kinetics of gold(I) phosphine complexes by nuclear magnetic resonance line shape analysis
Abstract
The 31P-{1H} n.m.r. spectra of [NEt4][AuBr2] with various amounts of the ligands PPhMe2 or PBun3 were studied at different ratios in CD2Cl2 solutions. The solutions show the presence of species having one, two, and three co-ordinated phosphine ligands (four in the case of PBun3), and these species exchange with one another at elevated temperatures. The entropies of activation (ΔS‡) for these processes are negative and the mechanism of exchange is thus associative in all cases.