Crystal and molecular structure and magnetic anisotropy of µ-oxo-bis-[NN′-ethylenebis(salicylideneiminato)iron( III )]–dichloromethane

The crystal structure of [Fe(salen)]2O, CH2Cl2 has been determined by three-dimensional X-ray methods. The crystals are monoclinic, space group P21/c, with Z= 4, and cell dimensions a= 12·44, b= 14·11, c= 19·83 Å and β= 110·4°. Atomic co-ordinates were obtained by Fourier methods and refined by full-matrix least-squares calculations to R 0·109 for 2836 independent reflexions. The Fe–O–Fe angle was found to be 142·2°. The magnetic anisotropy is discussed in terms of the ‘dipolar coupling’ approach to the spin–spin exchange in the molecule.