The preparation and crystal structure of dichlorotetrakis(trimethylenethiourea)nickel(II)

Abstract

Orange crystals of the complex NiCl₂([graphic omitted]:S)₄ have been investigated by three-dimensional X-ray diffraction at 120 ± 10°K. In a triclinic unit cell with a= 8·35, b= 8·69, c= 9·47 Å, α= 117·9, β= 74·3, γ= 93·3°, and space group P there is one centrosymmetric molecule. Patterson and electron-density difference syntheses served to locate the chlorine, sulphur, carbon, and nitrogen atoms which, with the nickel atom, were allowed anisotropic vibration parameters in the refinement. Refinement was carried out by the method of least squares to give R= 0·098; addition of hydrogen atoms in calculated positions with isotropic vibrations gave a final R value of 0·086 for 1657 observations.

The bond lengths are Ni–Cl 2·413, Ni–S 2·465 and 2·491, all ± 0·005 Å; average values for lengths in the ligand are CS 1·70, C–N 1·33, N–CH₂ 1·46, H₂C–CH₂ 1·49 Å, all ± 0·01 Å, not significantly different from those in trimethylenethiourea. Deviations from 90° in the angles, 92·5, 95·3, and 79·8°, subtended at the nickel atom are attributed to an intra-molecular N–H⋯Cl hydrogen bond.