Modulating Sterics in Trimethylplatinum(IV) Diimine Complexes To Achieve C–C Bond-Forming Reductive Elimination

Tuning the aryl substituents of <i>N</i>,<i>N</i>′-diaryl-2,3-dimethyl-1,4-diaza-1,3-butadiene (DAB) ligands promotes the challenging C–C bond-forming reductive elimination from Pt<sup>IV</sup> diimine complexes [(DAB)Pt(CH<sub>3</sub>)<sub>3</sub>(solvent)]<sup>+</sup> (<b>2</b>) under mild conditions. Experimental results and density functional calculations indicate that 2,6-aryl substitution promotes reductive elimination by facilitating dissociation of the coordinating solvent by close to 10 kcal mol<sup>–1</sup>, but too much steric bulk inhibits the formation of <b>2</b> in the one-electron outersphere oxidation of (DAB)Pt(CH<sub>3</sub>)<sub>2</sub> (<b>1</b>).