Evaluation of a silylene divalent lanthanide interaction in the metallocene complex (C5Me5)2Sm[SiNtBuCHCHNtBu]

An R2Si: --> Ln(11) complex (C5Me5)(2)Sm[Si-(NBuCHCHNBu)-Bu-t-Bu-t], 1, has been synthesized in 90% yield by reaction of (C5Me5)(2)Sm with 1,3-di-tert-butyl-2,3-dihydro-1H-1,3,2-diazasilol-2-ylidene in toluene. Structural features of the (C5Me5)(2)Sm part of 1 are similar to those in (C5Me5)(2)Sm(THF). The silylene ligand is located asymmetrically in the metallocene wedge with one tertbutyl group (Sm-C(Me) = 3.396(4) Angstrom) much closer to the metal than the other (Sm-C(Me) = 4.741(4) Angstrom). The Si-Sm(II) distance is 3.1910(1) Angstrom.