The divalent organosamarium complex (C
5Me
5)
2Sm(THF)
2 (
1) reacts in toluene with Me
3CCN to formthe insoluble trivalent cyanide complex [(C
5Me
5)
2SmCN]
n (
2). The Me
3CCN reaction was found to proceedthrough divalent (C
5Me
5)
2Sm(NCCMe
3)(THF)
x (
3). The bis(nitrile) analogue of
3, (C
5Me
5)
2Sm(NCCMe
3)
2(THF) (
4), is isolable from the reaction of
1 with Me
3CCN in THF and has been characterized by X-raycrystallography. Both
3 and
4 transform via C-C bond cleavage to form the cyanide product
2 and(C
5Me
5)
2Sm(N=CHCMe
3)(THF) (
5). Complex
5 is the product of insertion of Me
3CCN into a Sm-Hbond presumably formed by
-hydrogen elimination of a Me
3C intermediate. Complexes
2 and
5 canalso be generated by the stoichiometric reaction of crystalline
4 with
1 in toluene. Complex
5 can besynthesized directly from the reaction of [(C
5Me
5)
2Sm(
-H)]
2 with Me
3CCN and THF. Crystallographicdata on the related nitrile adducts [(C
5Me
5)
2Sm(NCCMe
3)(
-CN)]
3 (
6) and [(C
5Me
5)
2Sm(NCCMe
3)]
2(
-O) (
7) are also reported.