Formation of Ethylene-Bridged Dinuclear Ir<sup>III</sup> Species via M−C Coupling of Ir<sup>II</sup> and Ir<sup>II</sup>(ethene)

Ethene dissociation from [(Me<i><sub>n</sub></i>tpa)Ir<sup>II</sup>(ethene)]<sup>2+</sup>, induced by coordination of acetonitrile, causes a rapid and selective M−C coupling between Ir<sup>II</sup> and Ir<sup>II</sup>(ethene), resulting in ethylene-bridged dinuclear iridium(III) complexes of the composition [{(Me<i><sub>n</sub></i>tpa)Ir<sup>III</sup>(NCMe)}<sub>2</sub>(μ<sub>2</sub>-C<sub>2</sub>H<sub>4</sub>)]<sup>4+</sup> (<i>n</i> = 2, 3).