Imidazolidine bridged dinuclear iron amido complexes of biological relevance: Synthesis, characterization and redox properties

Abstract

<span style="font-size:14.0pt;font-family:" times="" new="" roman";="" mso-fareast-font-family:"times="" roman";mso-ansi-language:en-us;mso-fareast-language:="" en-us;mso-bidi-language:ar-sa"="">Binuclear Fe(III)-Fe(III) and Fe(III)-Zn(II) complexes of a new acyclic binucleating μ-bis(tetradentate) diamide ligand (H₅L) containing imidazoline backbone have been synthesized and characterized by elemental analysis, IR, UV -vis spectral, magnetic and electrochemical studies. The ligand reacts with FeCI₃.6H₂O and ZnCI₂.2H₂O in aqueous methanol in air affording crystalline compounds [Fe₂ (μ-Cl)(μ-H₂L)Cl₂) and [FeZn(μ-CI)(μ-H₂L)(H₂O)]CI in excellent yields. Both the Fe(III)-Fe(III) and Fe(III)-Zn(II) complexes have FeN₂O₂Cl₂/FeN₂O₃CI and ZnN₂O₂Cl coordination spheres. They represent a new type of imidazolidine bridged homo and heterodinuclear complexes of iron(III) with exogenous bridging by a μ-chloride function. Both electron transfer behaviour and magnetic properties of iron(III)-iron(III) complex are assessed with respect to a heterodinuclear iron(III)-zinc(II) complex in identical ligating environment.</span>