A New Series of Mono- and Dinuclear Hydridosilylrhodium(III) Complexes, RhCl(H)(SiAr₃)L₂and RhL(SiAr₃)H(μ-Cl)(μ-H)RhH(SiAr₃)L (L = P(i-Pr₃)). Preparation by Oxidative Addition of HSiAr₃and Molecular Structures of the Complexes

Reactions of triarylsilanes such as HSiPh 3, HSi(C 6 H 4 Me- p ) 3, HSi(C 6 H 4 OMe- p ) 3, HSi(C 6 H 4 Cl- p ) 3, HSi(C 6 H 4 F- p ) 3, and HSi(C 6 H 4 CF 3 - p ) 3 with RhClL 2 (L = P( i -Pr) 3 ) give a series of hydrido(triarylsilyl)rhodium(III) complexes, RhCl(H)(SiAr 3 )L 2 ( 1, Ar = Ph; 2, Ar = C 6 H 4 Me- p; 3, Ar = C 6 H 4 OMe- p; 4, Ar = C 6 H 4 Cl- p; 5, Ar = C 6 H 4 F- p; 6, Ar = C 6 H 4 CF 3 - p ). Tris(phenylethynyl)silane also reacts with the Rh(I) complex to give another oxidative-addition product, RhCl(H)[Si(C⋮CPh) 3 ]L 2 ( 7 ). X-ray analyses of 1 and 7 show a distorted-square-pyramidal coordination around the Rh center with the silyl ligand at the apical position. Prolonged reactions of HSiPh 3 and of HSi(C 6 H 4 OCF 3 - p ) 3 with RhClL 2 give dinuclear complexes, RhL(SiAr 3 )H(μ-Cl)(μ-H)RhH(SiAr 3 )L ( 8, Ar = Ph; 9, Ar = C 6 H 4 OCF 3 - p ). X-ray crystallography of 9 shows a molecular structure containing two Rh centers bridged with hydrido and chloro ligands. 1,1,3,3-Tetraisopropyldisiloxane undergoes oxidative addition of the Si H bonds to RhClL 2 to give a symmetric dinuclear Rh(III) complex with bridging hydrido, chloro, and disiloxanyl ligands, RhL(H)(μ-H)(μ-Cl)[μ-( i -Pr) 2 Si O Si-( i -Pr) 2 ]Rh(H)L ( 10 ).