SYNTHESIS AND PROPERTIES OF (AMINOMETHYL)NICKEL COMPLEXES - [(LI(OET(2)))(2)NI(CH(2)NC5H(10))(4)] - THE FIRST STRUCTURALLY CHARACTERIZED HOMOLEPTIC AMINOMETHYL COMPLEX OF A TRANSITION-METAL

Bu(3)SnCH(2)NR(2) (R(2)N = Me(2)N, C5H10N, Ph(2)N) react with BuLi to give R(2)NCH(2)Li . xthf (1a, R(2)N = Me(2)N, x = 0; 1b, R(2)N = C5H10N, x = 0; 1c, R(2)N = Ph(2)N, x = 1). 1a and 1b react with nickel halide-phosphine adducts to give very air-sensitive homoleptic aminomethyl complexes of nickel [{Li(OEt(2))}Ni-2(CH(2)NR(2))(4)] (2a, R(2)N = Me(2)N; 2b, R(2)N = C5H10N), which have been characterized analytically and spectroscopically by NMR. 2 is diamagnetic, is thermally very stable [Tdec 90-115 degrees C (2a), 95-110 degrees C (2b)], and reacts with water and alcohols to give R(2)NMe. The crystal structure of 2b (space group P2(1)/c; R = 0.0656) exhibits a molecular C-i symmetry. There is a planar NiC4 unit [d(Ni-C) 2.023(4), 2.032(4) Angstrom A] and a nearly trigonal planar coordination of Li at R(2)N and Et(2)O as well as Li contacts to nickel [d(Li-Ni) 2.592(2) Angstrom A] and to carbon atoms R(2)NCH(2)Ni of the piperidinomethyl ligands [d(Li-C) 2.166(7), 2.312(8) Angstrom A].