Kinetics of site-exchange reactions in di- and tri-methylplatinum(IV) glycinate complexes, from N.M.R. lineshape analysis

Abstract

Site-exchange reactions for PtMe₃(gly)(D₂O), and isomers of PtMe₂Br(gly)(D₂O) with D₂O coordinated trans to methyl have been studied, and rate constants determined by complete line shape analysis of ¹H n.m.r. spectra in the methyl region (gly = H₂NCH₂CO_2-). It is proposed that these reactions involve exchange of the labile water molecule with solvent water, with an associated migration of a donor atom (nitrogen or oxygen). Dissociative and associative (edge displacement) reaction pathways compete. The site-exchange reaction for PtMe₃(gly)₂- appears to occur by dissociation of a Pt-O bond.