Relieving Steric Strain at Octahedral Platinum(IV): Isomerization and Reductive Coupling of Alkyl and Aryl Chlorides

Oxidation of monocyclometalated platinum­(II) complexes results in octahedral platinum­(IV) complexes. Depending on the substitution, two different reactions occur: either a simple isomerization, resulting in the exchange of ligand positions, or a reductive coupling of aryl chloride. With a doubly cyclometalated complex, stability of the oxidized form is dependent on isomeric form: whereas the trans isomer is robust, being manipulable in air at room temperature, the cis isomer decomposes at −20 °C and above. Reductive coupling at this cis isomer is 100% selective for alkyl chloride over aryl chloride and is suggested to be a concerted process.