New organo- and amidozinc derivatives of primary amines

Abstract

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.