Mercury(II)-ethylenediamine complexes. Crystal and molecular structure of bis(ethylenediamine)mercury(II) diperchlorate and dithiocyanato(ethylenediamine)mercury(II)

Abstract

Crystals of bis(ethylenediamine)mercury(II) diperchlorate, (I), are monoclinic, a= 7.754(6), b= 11.618(7), c= 7.754(6)A, β= 100.38(3)°, space group P21, Z= 2. In the complex cation the mercury ion is co-ordinated by four nitrogen atoms (Hg–N 2.30–2.33 A) in a distorted tetrahedron (N–Hg–N ring angles 77.2 and 78.5°). The ethylenediamine ligands are bidentate, bonded in the usual gauche conformation. The amino-groups of one ligand form hydrogen bonds with the perchlorate oxygen (N–H ⋯ O 2.52 and 2.55 A).Crystals of dithiocyanato(ethylenediamine)mercury(II), (II), are orthorhombic, a= 12.029(8), b= 11.101(8), c= 7.069(5)A, space group Pna21, Z= 4. The structure is built up of discrete molecules in which mercury is co-ordinated by two nitrogen atoms (Hg–N 2.31 and 2.33 A) from ethylenediamine. In the gauche conformation, and by two sulphur atoms (Hg–S 2.428 and 2.529 A) from the thiocyanate ions in a distorted tetrahedron (N–Hg–N 80.0, S–Hg–S 111.3°). The thiocyanates are slightly bent, with S–C–N 175 and 178°.The structures were determined from diffractometer X-ray intensity data and refined by full-matrix least-squares methods to R 0.062 (I) and 0.044 (II) for 941 and 635 reflections, respectively.