A Redox‐Induced Spin‐State Cascade in a Mixed‐Valent Fe3(μ3‐O) Triangle. Issue 2 (5th December 2016)

• Record Type: Journal Article
• Authors: Govor, Evgen V.; Al‐Ameed, Karrar; Chakraborty, Indranil; Coste, Carla S.; Govor, Olena; Sanakis, Yiannis; McGrady, John E.; Raptis, Raphael G.
• Is Part Of: Angewandte Chemie international edition. Volume 56:Issue 2(2017)
• Page Start: 582
• Page End: 586
• Publication Date: 2016-12-05
• Subjects: density functional theory -- high-spin/low-spin transition -- iron complexes -- mixed-valence -- Mössbauer spectroscopy; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201610534
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: One‐electron reduction of a pyrazolate‐bridged triangular Fe3 (μ3 ‐O) core induces a cascade wherein all three metal centers switch from high‐spin Fe 3+ to low‐spin Fe 2.66+ . This hypothesis is supported by spectroscopic data ( 1 H‐NMR, UV‐vis‐NIR, infra‐red, 57 Fe‐Mössbauer, EPR), X‐ray crystallographic characterization of the cluster in both oxidation states and also density functional theory. The reduction induces substantial contraction in all bond lengths around the metal centers, along with diagnostic shifts in the spectroscopic parameters. This is, to the best of our knowledge, the first example of a one‐electron redox event causing concerted change in multiple iron centers. Abstract : One‐electron reduction flips a trinuclear, all‐high spin Fe 3+ complex to an all‐low spin, delocalized Fe 2.66+ . This is the first example of a one‐electron redox event causing concerted change in multiple iron centers.