The Metal Is the Kinetic Site of Protonation of (Diimine)Pt Dimethyl Complexes

• Published in: Journal of the American Chemical Society Vol. 124; no. 41; pp. 12116 - 12117
• Main Authors: Wik, Bror Johan, Lersch, Martin, Tilset, Mats
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 16-10-2002
• Subjects: Chemistry; Exact sciences and technology; Kinetics and mechanisms; Organic chemistry; Reactivity and mechanisms; Organic solvent; Platinum Organic compounds; Organic ligand; Reaction mechanism; Protonation; NMR spectrometry; Transition metal Complexes; Kinetic parameter; Rate constant; Experimental study
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja027649j

Protonolysis of (diimine)PtMe2 (1) complexes in CD2Cl2 containing CD3CN at −78 °C yields (diimine)PtMe2(H)(NCCD3)+ (4), (diimine)PtMe(NCCD3)+ (5), and methane. The relative yields of 5 and methane decrease with increasing concentrations of CD3CN. This is consistent with protonation of 1 occurring directly at the metal, rather than at a methyl group. The principle of microscopic reversibility then implies that the deprotonation in “Shilov-type C−H activation” occurs from a Pt(IV) hydridomethyl intermediate, rather than from a Pt σ-methane complex.