ALTERNATIVE LIGANDS .24. RHODIUM(I) COMPLEXES WITH P-DONOR AND SN-ACCEPTOR OR B-ACCEPTOR LIGANDS

Donor/acceptor ligands of the type Me2PCH2CH2SnMe3 (1), (Me2PCH2CH2)2SnMe2 (2), and Me2PCMe = CMeBMe2 (3), respectively, have been prepared by hydrostannylation of Me2PVi with Me3SnH or Me2SnH2 and by a multistep synthesis via Na[Me3BH], Na[Me3BC = CMe] using Me2PCl as partner, respectively. The new ligands were used to produce the Rh(I) complexes RhCl(CO)(Me2PCH2CH2SnMe3)2 (5), RhCl(CO)(Me2PCH2CH2)2SnMe2 (7), and RhCl(CO)(Me2PCMe = CMeBMe2)2 (8) by reactions of [Rh(CO)2Cl]2 (4) with the corresponding ligands. In addition, the VASKA type compounds RhCl(CO)(Me2PVi)2 (6) and RhCl(CO)(PMe3)2 were prepared in order to test an alternative route to 5 or to form the known adduct RhCl(CO)(PMe3)2.BBr3 (9). RhBr(CO)(PMe3)2 (10) and the binuclear system [RhBr(CO)PMe3]2 (11) were identified spectroscopically after working up the 1:1 reaction mixture of RhCl(CO)(PMe3)2 and BBr3. Reasonable pathways are suggested for their formation., Metal base" / acceptor interactions show up, on the one hand, in following reactions in case of the ligands with Sn acceptors, on the other hand, in significant changes of spectroscopic data for 8. New compounds of sufficient stability were characterized by analytical (C, H) and spectroscopic (MS, IR, NMR) investigations.