Activation of C-I Bond by Cycloplatinated(II) Complexes Comprising Tricyclohexylphosphine ligand: Kinetics and Mechanism Investigations

The cycloplatinated(II) complexes incorporating monophosphine ligands, with general formula of [Pt(C^N)(Me)(L)] (L = monophosphine ligand), are normally good choices in order to study of the mechanism of oxidative addition reaction with alkyl halides. [1]. Phosphine ligands are important in the sense that their electronic and steric effects, induced by their substituents, have a considerable impact on the rate constants and activation parameters of such reactions. Electron-withdrawing or electron-donating properties of the substituents and their Tolman cone angle values control the electronic and steric properties of the phosphine ligands, respectively [2]. Herein, we have investigated the kinetic and mechanism of the oxidation reaction of cycloplatinated(II) complexes incorporating tricyclohexylphosphine ligand (PCy3) by MeI (Fig. 1). The new Pt(IV) complexes have been identified by NMR spectroscopy and single crystal X-ray crystallography. The kinetic measurements, supported by the DFT calculations, have been performed using the UV-vis spectroscopy by monitoring the change in the absorbance spectra of Pt(II) complexes