Mixed-valence molecules: Electronic delocalization and stabilization

Recent work has revealed the first observation of stereochemical effects on intervalence charge transfer (IVCT) in di- and trinuclear mixed-valence complexes. The differential IVCT characteristics of the diastereoisomers of polypyridyl complexes of ruthenium and osmium offer a new and intimate probe of the fundamental factors that govern the extent of electronic delocalization and the barrier to electron transfer. These findings challenge prior assertions that the inherent stereochemical identity of such complexes would have no influence on the intramolecular electron-transfer properties of polymetallic assemblies. This article provides a brief review of the past 40 years of mixed-valence research and looks at recent progress in stereochemical effects on IVCT. The implications of the findings are considered within the context of the existing theoretical and experimental framework for IVCT.

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A Mixed-Valence Octanuclear Iron−Oxo Pyrazolate: Assessment of Electronic Delocalization by Structural and Spectroscopic Analysis

Inorganic Chemistry ◽

10.1021/ic801459s ◽

2008 ◽

Vol 47 (24) ◽

pp. 11734-11737 ◽

Cited By ~ 21

Author(s):

Indranil Chakraborty ◽

Peter Baran ◽

Yiannis Sanakis ◽

Athanassios Simopoulos ◽

Esteban Fachini ◽

...

Keyword(s):

Spectroscopic Analysis ◽

Mixed Valence ◽

Electronic Delocalization

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Effects of cooperative intermolecular interactions on the electronic delocalization in mixed‐valence biferrocenium trihalide compounds

The Journal of Chemical Physics ◽

10.1063/1.452084 ◽

1987 ◽

Vol 86 (4) ◽

pp. 2362-2374 ◽

Cited By ~ 44

Author(s):

Takeshi Kambara ◽

David N. Hendrickson ◽

Teng‐Yuan Dong ◽

Michelle J. Cohn

Keyword(s):

Intermolecular Interactions ◽

Mixed Valence ◽

Electronic Delocalization

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Electronic Coupling in Dimetallic Complexes with π-Conjugated Bridge

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2006.007 ◽

2006 ◽

Vol 6 (11) ◽

pp. 3347-3350 ◽

Cited By ~ 1

Author(s):

Min-Chul Chung ◽

Ho-Geun Ahn ◽

Chee-Hun Kwak ◽

Munetaka Akita

Keyword(s):

Radical Cation ◽

Coupling Parameter ◽

Mixed Valence ◽

Absorption Peak ◽

Electronic Coupling ◽

Class Iii ◽

Effective Coupling ◽

Electronic Delocalization

Compound 2, [(η5-C5Me5) Fe(dppe)]2 (μ-C≡C–CH=CH–C≡C), was prepared by the reaction of compound 1, [η5-C5Me5) Fe(dppe)]+2 (μ2-C=CH–CH=CH–HC=C) · (PF 6)2–, with KOBut. Compound 2 showed two quasi-reversible one-electron oxidations at −0.674 and −0.253 V, respectively. The comproportionation constant, Kc, was calculated from these measurements. The mixed-valence(MV) radical cation 2+ showed an absorption peak at 1586 nm, which was assigned to the MV π–π band of the delocalized complex (Robin-Day Mixed-valence Class III) and the effective coupling parameter, Hab, is consistent with the presence of electronic delocalization.

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