Crystal structure of a new mercury(II) complex dichloromercury–2/3thiourea

Abstract

The title compound has been isolated. Its composition and crystal structure have been determined from single-crystal X-ray photographic data by the heavy-atom method, and refined by block-diagonal least-squares to R 0·10 for 408 visually estimated reflections. Crystals are monoclinic, space group P2₁/c, a= 8·00(1), b= 14·99(2), c= 7·21(1), β= 93·5(5)°, Z= 6 (for HgCl₂,2/3tu).

The complex is effectively [{HgCl(tu)}Cl]_n, n//₂HgCl₂, (tu = thiourea), and consists of mercury atoms co-ordinated by thiourea (Hg–S, 2·40 Å) and chlorine (Hg–Cl, 2·39 Å, S–Hg–Cl, 155°); a further chlorine bridges these units in an infinite chain (Hg–Cl 2·84 and 2·94 Å) parallel to c. Discrete HgCl₂, molecules, centred on special positions, occupy interstices between the chains.