Tracing the Iron Nitrosyl Complex [Fe(2,2′-bipyridine)(CN)3(NO)]

• Published in: European journal of inorganic chemistry 2015-02, Vol.2015 (6), p.1033-1040
• Main Authors: Foi, Ana, Di Salvo, Florencia, Doctorovich, Fabio, Roy, Tapashi G., Stirnat, Kathrin, Biewer, Christian, Klein, Axel
• Format: Article
• Language: English
• Subjects: Di­imines; Electrochemistry; IR spectroscopy; Iron; Nitrogen oxides
• ISSN: 1434-1948; 1099-0682
• DOI: 10.1002/ejic.201403145

The previously reported complex [Ph4P][Fe(bpy)(CN)3(NO)] (bpy = 2,2′‐bipyridine) was synthesised and characterised in detail using UV/Vis absorption and IR spectroscopy, cyclic voltammetry, and single‐crystal XRD. Detailed spectroelectrochemical (UV/Vis, IR and EPR) insight adds perfectly to the previous electrochemical characterisation of this complex. The description of this {Fe(NO)}7 complex as a low‐spin FeII–NO· system based on the spectroscopic results is supported by DFT calculations. Reversible oxidation leads to the corresponding {Fe(NO)}6 (FeII–NO+) complex, whereas the reduction to the formal {Fe(NO)}8 species [presumably (FeII–NO–)] occurs irreversibly. When trying to synthesise further derivatives that contain other α‐diimine ligands, only for the 1,10‐phenanthroline (phen) derivative were some results obtained. For other ligands the obtained materials were too reactive. The reasons for such behaviour are also discussed. The previously reported complex [Ph4P][Fe(bpy)(CN)3(NO)] (bpy = 2,2′‐bipyridine) was synthesised and a detailed structural (single‐crystal XRD), (spectro)electrochemical and spectroscopic insight is provided that adds perfectly to the previous electrochemical characterisation.