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

Abstract

The crystal and molecular structure of [(Fe salen)₂O],2py (salen =NN′)-ethylenebis(salicylideneiminato, py = pyridine) has been determined by single-crystal X-ray analysis. The crystallographic asymmetric unit comprises one dimeric molecule and two non-bonded pyridine molecules in a triclinic cell of dimensions, a= 12·73, b= 13·73, c= 13·92 Å, α= 118·75, β= 74·15, γ= 116·17°; space group P. The iron atoms are joined by a single oxygen atom and both are five-co-ordinate with a distorted square pyramidal geometry. The mean Fe–O(bridge) bond length is 1·80 Å and the bridging angle Fe–O–Fe is markedly bent at 139°. The properties of the dimeric molecule are compared with those of other oxo-bridged iron(III) and manganese(III) dimers and also with the closely related [Fe salen Cl]₂ dimer and Fe salen Cl monomer.