ALTERNATIVE LIGANDS .23. RHODIUM(I) COMPLEXES WITH DONOR-ACCEPTOR LIGANDS OF THE TYPE-(ME2PCH2CH2)2SIX2 AND (2-ME2PC6H4)SIXME2 (X = F, CL)

Donor/acceptor ligands of the type (Me2PCH2CH2)2SiX2 and (2-Me2PC6H4)SiXMe2 (X = F, Cl) react with [Rh(CO)2Cl]2 (1) to give the mononuclear complexes RhCl(CO)(Me2PCH2CH2)2SiX2 [X = F (4), Cl (5)] and RhCl(CO)[(2-Me2PC6H4)SiXMe2]2 [X = F (8), Cl (9)], respectively. In case of the ligands (Me2PCH2CH2)2SiCl2 (3) and (2-Me2PC6H4)SiClMe2 (7) the Rh(I) complexes formed in the first step partly undergo oxidative addition reactions of SiCl bonds yielding rhodium(III) compounds of low solubility. Only for 8 the coordination shifts DELTA-delta = delta(complex)-delta(ligand) and coupling constants give some indication to possible Rh --> Si interactions. However, the molecular structure of 8 determined by X-ray diffraction does not show RhSi or RhF bonding contacts. The new compounds were characterized by analytical (C, H) and spectroscopic investigations (MS, IR, NMR).