3-Ammonio-pyridinium tetra-bromido-mercurate(II) monohydrate

Abstract

The asymmetric unit of the title compound, (C(5)H(8)N(2))[HgBr(4)]·H(2)O, consists of one cation, one anion and one water mol-ecule. The anion exhibits a distorted tetra-hedral arrangement about the Hg atom. The crystal structure contains alternating sheets of cations (in the ac plane) and stacks of anions. Several strong hydrogen-bonding inter-actions (pyN-H⋯Br and C-H⋯Br; py is pyridine), along with O-H⋯Br inter-actions, connect the sheets of cations to the stacks of anions. Cation-cation π-π stacking is also present (C⋯C distances in the range 3.424-3.865 Å). The shortest Br⋯Br distance is 3.9527 (9) Å.

Fig. 1.

A view of the asymmetric unit with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.

Fig. 2.

A cation···2H2O···cation supramolecular motif, via significant N—H···O and O—H···O hydrogen bonding. Hydrogen bonds are shown as dashed lines.

Fig. 3.

Cationic sheets in the ac plane. π···π stacking is represented as double headed arrows. Solid double headed arrows are intra-layer interactions, while dashed double headed arrows are inter-layers interactions.

Fig. 4.

Overall packing of alternating anion stacks and sheets of cations and water molecules. Hydrogen atoms omitted for clarity.