Silabenzene and Disilabenzene Complexes of Ruthenium

The syntheses of sila- and disilabenzene complexes of "Cp*Ru" (Cp* = C5Me5) are described. Li[C5H5SiH(tBu)] reacted with [Cp*RuCl]4 to give the neutral silacyclohexadienyl complex Cp*Ru[η5-C5H5SiH(tBu)] (2), characterized by NMR spectroscopy. Reaction of 2 with the Lewis acid B(C6F5)3 gave the product of Si−H abstraction, [Cp*Ru(η6-C5H5SitBu)][BH(C6F5)3] (3). Complex 3 represents the first example of an isolated silabenzene complex. The characterization of 3 follows from 1H, 13C, 29Si, 19F, and 11B NMR and IR spectroscopies. Finally, trans-1,4-dihydrohexamethyl-1,4-disilacyclohexa-2,5-diene reacted with Cp'(PMe3)2RuCH2SiMe3 (Cp' = C5Me4Et) to give Cp'(PMe3)RuH(η2-hexamethyl-1,4-disilabenzene) (4), whose structure (by X-ray crystallography) may be described as a metallodisilanorbornadiene.