Low-coordinate volatile Group 12 amides: syntheses and crystal structure determinations of dimeric {M{N[Si(CH3)(2)CH2CH2Si(CH3)(2)]}(2)}(2); M = Zn, Cd and monomeric Hg{N[Si(CH3)(2)CH2CH2Si(CH3)(2)]}(2)

Anhydrous group 12 metal (Zn, Cd, Hg) dihalides react with 2 equiv. of lith ium 2,2,5.5-tetramethyl-2,5-disila- 1-aza-cyclopentanide Li{N[Si(CH3)(2)CH2 CH2Si(CH3)(2)]} in Et2O to afford dimeric zinc and cadmium amide complexes {M{N[Si(CH3)(2)CH2CH2Si(CH3)(2)]}(2))(2) (M=Zn (1), M=Cd (2)), as well as t he monomeric mercury derivative Hg{N[Si(CH3)(2)CH2CH2Si(CH3)(2)]}2 (3). All prepared complexes represent volatile solids with considerable gas-phase s tability. Molecular structures determined by the single crystal X-ray diffr action technique show that zinc (1) and cadmium (2) amide examples contain three-coordinate metal atoms forming a slightly distorted M2N2-core with th e bridging nitrogens, while the corresponding mercury derivative (3) consis ts of monomeric molecules with the central metal linearly coordinated by bo th nitrogen atoms. (C) 2001 Elsevier Science Ltd. All rights reserved.