Synthesis, Crystal Structure, and Magnetic Properties of a Very Rare Double μ‐1,1‐Azido‐ and a μ‐1,1‐(OMe)‐Bridged FeIII Dimer Containing a N,N,O‐Donor Tridentate Schiff Base Ligand

Abstract

AbstractTwo new FeIII complexes, [Fe2L2(μ‐OMe)2(NCS)2] (1) and [Fe2L2(μ‐N3)2(N3)2] (2), have been synthesized using a N,N,O‐donor tridentate Schiff base ligand HL {2‐[(2‐dimethylaminoethylimino)methyl]phenol}, the condensation product of salicylaldehyde and N,N‐dimethyl‐1,2‐diaminoethane. The complexes were characterized by X‐ray structural analyses and variable‐temperature magnetic susceptibility measurements. Both crystal structures are centrosymmetric dimers containing two FeIII atoms, which are bridged in compound 1 by two methoxy anions and in compound 2 by two μ‐1,1‐azides. The chelating tridentate Schiff base and a terminal thiocyanato (for 1) or azido (for 2) group complete the hexacoordination of the distorted octahedral environment of each iron center. The magnetic properties of compound 1 show the presence of antiferromagnetic exchange interactions mediated by double methoxy bridges (J = –29.45 cm–1). Compound 2 shows the presence of very weak ferromagnetic exchange interactions mediated by double μ‐1,1‐N3 bridges (J = 1.08 cm–1).