Cyclometallation on platinum(ii) complexes; the role of the solvent and added base donor capability on the reaction mechanismsElectronic supplementary information (ESI) available: Listings of selected bond lengths (?) and angles (�) for complex 2 with estimated standard deviations, crystallographic and refinement data for complex 2 and listing of observed rate constants for the cyclometallation reaction of complex 1. Plot of the molecular structure of complex 2 and that of the observed rate constants corresponding to the first reaction step determined when proton sponge or neat solvent were used. 1H NMR spectra of the mixture of Z and E isomers of complex 1. See http://www.rsc.org/suppdata/dt/b3/b306243k/