Preparation of Mercury(II) Complexes of Tris[(2-pyridyl)methyl]amine and Characterization by X-ray Crystallography and NMR Spectroscopy

Abstract

The complexation of Hg(II) by the tripodal ligand tris[(2-pyridyl)methyl]amine (TMPA) was investigated by solution state NMR and X-ray crystallography. Mercury coordination compounds exhibiting rarely observed room-temperature solution state NMR 1H199Hg and 13C199Hg satellites were characterized. Solvent, counterion, temperature, and concentration effects on solution state NMR properties were investigated. The solution state NMR were correlated with two solid state structures. The eight-coordinate complex [Hg(TMPA)2](ClO4)2 (1) crystallizes in the monoclinic space group P21/n with a = 9.735(10) A, b = 10.963(2) A, c = 18.553(34) A, β = 103.81(12)°, and Z = 2. The mercury is at the inversion center of a bicapped trigonal antiprism. The Hg−Namine distance is 2.560(3) A, and the average Hg−Npyridyl distance is 2.58(2) A. The five-coordinate complex [Hg(TMPA)Cl]2(HgCl4) (2) crystallizes in the triclinic space group P1 with a = 11.887(2) A, b = 13.260(2) A, c = 15.278(4) A, α = 112.27(2)°, β = 109.39(2)°, γ =...