Stereochemistry of rigid chelate–metal complexes. Part I. The crystal structure of dichloro-(2,9-dimethyl-1,10-phenanthroline)zinc(II)

Abstract

The crystal structure of dichloro-(2,9-dimethyl-1,10-phenanthroline)zinc(II), C₁₄H₁₂Cl₂N₂Zn, has been determined from three-dimensional equi-inclination Weissenberg X-ray diffraction data with 1082 visually estimated reflections. The orthorhombic unit-cell, space group P_nam, has dimensions a= 11·23(2), b= 17·68(2), and c= 7·487(9)Å, with Z= 4. The structure was refined by least squares to a conventional R of 0·091. Each molecule occupies a special position in the cell, having all its atoms in a crystallographic mirror-plane, except for the chlorine atoms which straddle this plane. The zinc atom has a distorted tetrahedral environment. The observed deviation from tetrahedral bond angles is due to the rigidity of the nitrogen atoms in the chelate ring system [Zn–N, 2·059(11), 2·074(9); Zn–Cl, 2·204(3)Å; N–Zn–N, 81·5(3)°; Cl–Zn–Cl, 120·3(1)°].