Sterically demanding multidentate ligand tris[(2-(6-methylpyridyl))methyl]amine slows exchange and enhances solution state ligand proton NMR coupling to (199)Hg(II).

The solution state coordination chemistry of Hg(ClO(4))(2) with tris[(2-(6-methylpyridyl))methyl]amine (TLA) was investigated in acetonitrile-d(3) by proton NMR. Although Hg(II) is a d(10) metal ion commonly associated with notoriously rapid exchange between coordination environments, as many as six ligand environments were observed to be in slow exchange on the chemical shift time scale at select metal-to-ligand ratios. One of these ligand environments was associated with extensive heteronuclear coupling between protons and (199)Hg and was assigned to the complex [Hg(TLA)](2+).

Correlation of a Solution-State Conformational Change between Mercuric Chloride Complexes of Tris[(2-(6-methylpyridyl))methyl]amine with X-ray Crystallographic Structures.

Solution-state NMR and X-ray crystallography were used to investigate the complexation of HgCl(2) by the potentially tetradentate ligand tris[(6-methyl-2-pyridyl)methyl]amine (TLA) in acetonitrile. A change in the ligand conformation as a function of the metal-to-ligand ratio could be indirectly monitored through large changes in (3)J((1)H(199)Hg) to the methylene protons at -40 degrees C. The solution-state NMR were correlated with two solid-state structures.