On the Activation of Chloromethanes by Cyclometalated [Pt(bipy – H)] + in the Gas Phase: A Mechanistic Study

Abstract

The gas-phase ion/molecule reactions of cyclometalated [Pt(bipy – H)] + (bipy = 2,2′-bipyridine) with the chloromethanes CH 4- n Cl n ( n = 1–4) were investigated and mechanistic features were derived from deuterium labeling experiments. The initial step corresponds to an insertion of the platinum center into the C–Cl bond of the chloromethanes which is either followed by an intramolecular migration of the (halogenated) methyl group to the platinum-bound carbon atom of the aryl ring or for the substrates CHCl 3 and CCl 4 by the losses of neutral or cationic CHCl 2 and CCl 3 fragments. In all reactions, apart from that with CH 3Cl, transfer of CH 2- n Cl n ( n = 0–2) to the (bipy – H) ligand is observed; this process corresponds to a platinum-mediated C–C bond formation.