Crystal and molecular structure of a nickel(II) macrocyclic tetra-imine complex: 5,7,7,12,12,14-hexamethyl-1,4,8,11-tetra-azacyclotetradeca-4,8,10,14-tetraenenickel(II) perchlorate

Abstract

The structure of the title compound has been determined by single-crystal X-ray analysis from photographic data and refined by least-squares techniques to R 0·12 for 1229 independent reflections. Crystals are orthorhombic, space-group Pbcn, with a= 10·62, b= 11·18, and c= 18·81 Å, Z= 4. A crystallographic two-fold axis lies in the approximate plane of the macrocyclic cation, requiring the nickel ion to lie in the mean plane of the four nitrogen atoms, these deviate ± 0·18 Å from the co-ordination plane, indicating some lack of flexibility in the macrocycle. Strain in the complex is also discussed in terms of deviations of the macrocycle bond and torsion angles from the expected strain-free values. This complex is compared with the related di-imine complex 5,7,7,12,12,14-hexamethyl-1,4,8,11-tetra-azacyclotetradeca-4,14-dienenickel(II) perchlorate.