Control of Redox Potential by Deprotonation of Coordinated 1H-Imidazole in Complexes of 2-(1H-Imidazol-2-yl)pyridine

✍ Scribed by Gilles Stupka; Ludovic Gremaud; Alan F. Williams

• Book ID: 102259215
• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: German
• Weight: 116 KB
• Volume: 88
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.200590033

✦ Synopsis

Abstract

Complexes [ML~3~]^2+^ of the bidentate ligand 2‐(1__H__‐imidazol‐2‐yl)pyridine were prepared with iron(II), cobalt(II), and ruthenium(II). The electronic spectra suggest the ligand to be a weaker σ‐donor and π‐acceptor than the closely related 2,2′‐bipyridine. The complexes are readily deprotonated by addition of base, and the effect of the deprotonation is to lower the M^III^/M^II^ redox potential by roughly 900 mV. This is roughly 75% of the drop observed for related complexes of 2,6‐di‐1__H__‐imidazol‐2‐ylpyridine, and suggests the effect to be largely coulombic in origin.