Migrations in a Polysilyl Complex of Rhodium. Trapping of an Apparent Silylene Intermediate and Observation of Reversible Si−Si Bond Reductive Elimination

Reaction of (Me 3 P) 3 RhCl with (THF) 3 LiSi(SiMe 3 ) 3 in the presence of 2-butyne or diphenylacetylene generates (Me 3 P) 2 (Me 3 Si)RhSiMe 2 C(R) C(R)SiMe(SiMe 3 ) ( 1, R = Me; 2, R = Ph). These complexes undergo a fluxional process which exchanges the SiMe 3 groups, apparently by Si−Si bond reductive elimination/oxidative addition.