Synthesis and structures of chiral halo[N,N-dimethyl-alpha-(2-naphthyl)ethylamine-3,C,N] mercury (II) complexes

HgCl2 reacts with enantiomerically pure 3-lithio-(S)-(-) or (R)-(+)-N,N-dim ethyl-alpha-(2-naphthyl)ethylamine, (S) or (R)-LiTMNA, to produce (S)(c)(R) (Hg)-{HgCl[C10H6CH(Me)NMe2]}, 2a', or (S)(c)(R)(Hg)-{HgCl[C10H6CH(Me)NMe2]} , 2a, in fair yields, The bromide (2b) and iodide (2c) analogs were prepare d in good yields by reaction of 2a with NaBr and NaI, respectively. The cry stal structures of 2a', 2b and 2c show that the Hg atom in each compound is three-coordinate, T-shaped, and slightly pyramidal in the solid slate. The se three compounds form exclusively as the (S)(c)(R)(Hg) or (R)(c)(S)(Hg) d iastereomers with average Hg-C and Hg-N distances of 2.08 (2) Angstrom and 2.65 (2) Angstrom, respectively. The Hg-N bond is weak and is easily cleave d in solution to form temperature-dependent equilibrium mixtures of two- an d three-coordinate species as deduced from variable temperature NMR spectro scopy. (C) 1999 Elsevier Science B.V. All rights reserved.