Synthesis, structure, and magnetic properties of the iron(iii) iodide complex with the 3,5-di-tert-butylcatecholate ligand

The reaction of iron( ii ) iodide with 3,5-di- tert -butyl- o -benzoquinone (3,5-DBBQ) in anhydrous diethyl ether afforded the heteroleptic binuclear complex [Fe 2 I 2 (3,5-DBCat) 2 (Et 2 O) 2 ] ( 1 ) (3,5-DBCat is 3,5-di- tert -butylcatecholate). The crystal structure of the newly synthesized compound 1 was determined by single-crystal X-ray diffraction analysis, and its phase purity was confirmed by powder X-ray diffraction. Quantum chemical calculations indicate that the iron(III) ions are in the high-spin state and the redox-active ligand is in the dianionic catecholate form. Magnetochemical measurements of 1 in the temperature range of 2–300 K revealed intramolecular antiferromagnetic exchange interactions between Fe III ions, which is consistent with quantum chemical calculations.