Coordination of carboxamido nitrogen to tervalent iron: insight into a new chapter of iron chemistry

Although coordination of carboxamido nitrogen to Fe(III) center has been assumed to be improbable, research work during the past few years has demonstrated that Fe(III) complexes with ligated carboxamido nitrogens can be readily synthesized. The Fe(III)–Namido bond distances lie in the range of 1.8–2.2 Å in the various low spin and high spin Fe(III) complexes. These complexes are stable in aqueous media and their redox parameters indicate that the carboxamido nitrogens provide significant stability to the Fe(III) center.