Synthesis, structures, and magnetic behavior of two high-spin binuclear Fe(III) complexes

Abstract

The reaction of 2-t-butyl-4-ethylphenol, formaldehyde, and 2-amino propanol or 3-amino-1-propanol at 2 : 2 : 1 provides N-(1-ethanol)-N,N-bis(3-t-butyl-5-ethyl-2-hydroxybenxyl)amine (H₃L′) and N-(3-amino-1-propanol)-N,N-bis(3-t-butyl-5-ethyl-2-hydroxybenxyl)amine (H₃L″), respectively. In the presence of Et₃N, the reaction of FeCl₃ · 6H₂O and H₃L′ or H₃L″ gives dinuclear Fe(III) complexes [] 1 and [] 2, respectively, which have been characterized by X-ray crystallography, magnetic measurements, and cyclic voltammetry (CV). Magnetic studies indicate significant antiferromagnetic coupling between the iron(III) centers for 1 and 2. The values obtained for the coupling constants (J) are −12.35 cm⁻¹ for 1 and −16.26 cm⁻¹ for 2. CVs of 1 and 2 reveal one reversible wave at −0.80 and −0.82 V versus AgCl/Ag, respectively, which can be ascribed to redox coupling of Fe^IIIFe^II/Fe^IIIFe^III.

Keywords:

• Dinuclear Fe(III) complexes
• Crystal structures
• Magnetic properties
• Electrochemical properties

Acknowledgments

This work was supported by the Research Foundation for Returned Chinese Scholars Overseas of Chinese Education Ministry (No. B7050170), the National Science Foundation of China (No. 20971045), the Student Research Program (SRP) of South China University of Technology and Analytical and Testing Center of South China University of Technology.