Crystal structure of chlorobis(thiourea)mercury(II) chloride

Abstract

The crystal structure of the title compound, has been determined by single-crystal X-ray diffraction by conventional heavy-atom methods, and refined by block-diagonal least-squares to R 0·08 for 359 visually estimated reflections. Crystals are orthorhombic, space group Pmmn, a= 6·44 ± 0·01, b= 12·76 ± 0·02, c= 5·91 ± 0·01 Å; Z= 2.

The mercury atom is co-ordinated in an unusual approximately trigonal planar conformation by the two equivalent thiourea sulphur atoms and a chlorine atom (Hg–S 2·42 ± 0·01, Hg–Cl 2·57 ± 0·01 Å; S–Hg–Cl 110·8 ± 0·2, S–Hg–S 138·4 ± 0·2°). The other ‘ionic’ chlorine atom lies normal to this plane, between and equidistant from a pair of mercury atoms at 3·22 Å. The thiourea molecules and the mercury and co-ordinated chlorine atoms are coplanar (Hg–S–C 110·0 ± 0·9°); their intramolecular geometry is as expected.