STRUCTURE OF [NH3(C2H5)]2[HG(CN)2CL2]

The structure of bis(ethylammonium) dichlorodicyanomercurate consists of slightly deformed tetragonal nets of Cl atoms parallel to (100) at x = 0.25 and 0.75. Half of the chlorine squares are nearly centred by Hg atoms resulting in a chess-board arrangement. The environment of th e Hg atom is augmented to a distorted octahedron by two CN groups near ly perpendicular to the chlorine net. The C2H5NH3 groups are located a bove and below the non-centred chlorine squares. Two H atoms of the NH 3 group bridge to Cl atoms of the neighbouring net with distances of 2 .233 (2) and 2.442 (2) angstrom. The shortest distance from the third H atom to the N atom of the CN group located in the next slice is 2.07 8 (7) angstrom. Thus the two slices may be regarded as being tied up b y hydrogen bridges. The nets are shifted against each other in the b d irection according to the glide operation a.