Conformational influences in copper co-ordination compounds. Part II. Crystal structure of the methylammonium perchlorate adduct of NN′-ethylenebis(acetylacetoneiminato)copper(II)

Abstract

A three-dimensional X-ray analysis of the purple, needle-like crystals of the methylammonium perchlorate adduct of NN′-ethylenebis(acetylacetoneiminato)copper(II) indicates that the crystal structure is to be described as a simple lattice compound of complex molecules and methylammonium and perchlorate ions. There are two formula units in a monoclinic unit cell of dimensions a= 11·77, b= 7·25, c= 10·89, Å, β= 93° 30′. The space group is thought to be P2₁ although the symmetry conforms closely to P2₁/m. An unexpected result is the coplanarity of all atoms of the chelate molecule, including the two bridging carbons, with the consequent adoption of the unusual cis-conformation for the ethylene group.