Crystal and molecular structure of the high-spin five-co-ordinate complex aquo-NN′-ethylenebis-(3-methoxysalicylideneiminato)cobalt(II)

Abstract

The crystal structure of the title compound has been determined from three-dimensional X-ray data by conventional Fourier methods. Crystals are orthorhombic, space group Pnma, with Z= 4 and cell parameters a= 8·98, b= 24·95, c= 7·72 Å. A least-squares refinement, based on 365 independent reflexions, reduced R to 0·058. The crystals consist of five-co-ordinate molecules in an umbrella shape, held together by van der Waals forces and hydrogen bonds. The cobalt atom is displaced 0·43 Å from the basal plane towards the apical water molecule [Co–O 2·12(2)Å]. The basal Co–O and Co–N bond lengths [1·95(1) and 2·05(1)Å] are significantly greater than those found in analogous low-spin complexes. Such structural results may be indicative of a smaller metal–ligand π-bonding contribution in high-spin quadridentate Schiff-base complexes as compared with the low-spin species.