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

Tuning the aryl substituents of N,N'-diaryl-2,3-dimethyl-1,4-diaza-1,3-butadiene (DAB) ligands promotes the challenging C-C bond-forming reductive elimination from Pt-IV diimine complexes [(DAB)Pt(CH3)(3)(solvent)](+) (2) 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(-1), but too much steric bulk inhibits the formation of 2 in the one-electron outersphere oxidation of (DAB)Pt(CH3)(2) (1).