Kinetically Stabilized P,Si-Chelate Metal Complexes:  Isolation, Isomerization, and X-ray Structural Analysis

A series of kinetically stabilized trans bis-chelate metal complexes, trans -(Cab P, Si ) 2 M (M = Pt 4; M = Pd 7a ), bearing bulky o -carboranylphosphine tethers, have been synthesized from the reaction of the phosphinosilanes 2 with d 10 metal complexes. In the presence of dimethyl acetylenedicarboxylate (DMAD), the trans isomer 4 thermally rearranges to the thermodynamically favored cis isomer, cis -(Cab P, Si ) 2 Pt 5 .