Synthesis and Characterization of Cationic Rhodium Complexes with Stable Silylenes

Two cationic rhodium(I)−tetrasilylene complexes, (4; BArF =
tetrakis[3,5-bis(trifluoromethyl)phenyl]borate) and (5), were prepared from
[Rh(cod)2]BArF and 1,3-di-tert-butyl-2,3-dihydro-1H-1,3,2-diazasilol-2-ylidene (1) or its saturated analogue
2, respectively (Figure ). The two complexes were
characterized by X-ray analysis and NMR spectroscopy.
The crystal structures revealed a square-planar coordination geometry for both complexes. Only tetrakis(silylene) complexes were formed, even in the presence
of less than 4 equiv of silylene.