Crystal Engineering with Mercuric Chloride

Two new network solids containing mercury ions are reported. The structure of HgCl4·H2tpt·H2O (tpt =
1,3,5-tri(4-pyridyl)-2,4,6-triazine) contains H2tpt2+ cations connected into 1D zigzag chains via hydrogen bonding between
protonated and unprotonated pyridyl groups of adjacent cations. The third pyridyl group of each H2tpt2+ cation is also
protonated and hydrogen-bonds to tetrahedral HgCl42- anions that lie as appendages to the main hydrogen-bonded chain.
(HgCl2)2(hmt) (hmt = hexamethylenetetramine) contains HgCl2 and hmt molecules. The mercury is pseudo-octahedral,
coordinating to two trans chloride ligands (Hg−Cl = 2.351(1) Å) and making four much longer equatorial interactions
with hmt molecules (Hg−N = 2.735(4) Å) and adjoining HgCl2 molecules (Hg−Cl = 3.105(1) Å). The long Hg−N interactions
link the two species into 2D (4,4) sheets, while long Hg−Cl interactions connect these sheets into an overall 3D network
through chains of rhombohedral Hg−Cl···Hg−Cl··· motifs.