New organo- and amidozinc derivatives of primary amines.
Five new zinc derivatives of primary amines [R'ZnN(H)R]2 [R = SiPh3, R' = Me (1), N(SiMe3)2 (4); R = Si(NMe2)3, R' = Me (2), Et (3), N(SiMe3)2 (5)] have been synthesised by reaction of R'2Zn and H2NR. All five species are dimers in which the N-H groups are disposed in a trans manner about a central Zn2N2 ring. In 1 and 4 the coordination at zinc is trigonal planar, while in 2, 3, 5 the zinc is in a distorted tetrahedral environment due to additional Me2N: → Zn coordination from one SiNMe2 group. 5 was found to be generally resistant to NH deprotonation by bases such as MN(SiMe3)2 (M = Li, K) or Zn[N(SiMe3)2]2, but reacts with Sn[N(SiMe3)2]2 to give the tin-free, tetrameric mixed zinc-imido/amido species, [{(Me3Si)2N}{(Me2N)3SiN(H)}{(Me2N)3SiN}Zn2]2 (6) which can be viewed as part of a hexameric Zn6N6 drum which has lost a Zn2N2 ring.