Syntheses and X-ray crystal structures of monomeric zinc and mercury bis(silylamides)

Abstract

Lithium amides Li[N(SiMe 3)(R)] (R = –SiPh 2 t Bu and adamantyl), generated in situ from the reaction of the corresponding secondary amine with n butyllithium, have been treated with anhydrous ZnCl 2 and HgBr 2 to yield the corresponding homoleptic metal silylamides Zn[N(SiMe 3)(SiPh 2 t Bu)] 2 ( 1), Hg[N(SiMe 3)(SiPh 2 t Bu)] 2 ( 2), Zn[N(SiMe 3)(Ad)] 2 ( 3) and Hg[N(SiMe 3)(Ad)] 2 ( 4). All complexes are monomeric and have been fully characterized by 1H NMR, 13C NMR spectra and elemental analyses, as well as single crystal X-ray crystallography. X-ray diffraction analyses indicated that the complexes 1– 4 are two coordinate with roughly linear N–M–N arrangements, although the N–Zn–N angle in 1 deviates significantly at 167.87°. An unusual feature of the adamantyl-containing compounds is that 3 adopts a syn arrangement of the Ad groups, while 4 shows an anti arrangement in the solid state. We have investigated the interactions of these complexes with CO 2 and have determined that 1, 2 and 4 do not react with CO 2 while 3 reacts to form (Ad)N C N(Ad).