Contrasting electroabsorbance behavior of two borderline class II/class III mixed-valence systems

Peter H. Dinolfo, Robert D. Williams, Joseph T Hupp

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Intervalence Stark effect spectroscopy of a symmetrically substituted and an asymmetrically substituted derivative of the Creutz-Taube ion, (NH3)5Ru-pyrazine-Ru(NH3)55+, is reported. Like the formally mixed-valent parent ion, both appear to lie near the boundary between valence delocalization and valence localization. Remarkably, despite the close structural similarities of the two compounds investigated, the corresponding electroabsorbance spectra are grossly different. Furthermore, neither spectrum is well fit by a classic Liptay approach. An alternative, qualitative approach that allows for the possibility that the externally applied electric field itself affects the degree of valence delocalization and, therefore, the electroabsorbance spectrum, was employed. The alternative approach relies upon the availability of compounds closely analogous to the investigated compounds, but differing slightly in degree of redox asymmetry. A subtle method for creating such compounds is to partially encapsulate a parent compound with a crown ether, such that a lower symmetry assembly is obtained. Using this approach the unusual Stark responses, including the disparate responses for symmetric vs. asymmetric structures, are reasonably well reproduced. Intervalence-enhanced resonance Raman spectra provide additional support for the proposed interpretation.

Original languageEnglish
Pages (from-to)28-38
Number of pages11
JournalChemical Physics
Volume319
Issue number1-3
DOIs
Publication statusPublished - Dec 7 2005

Fingerprint

Ions
Crown Ethers
Pyrazines
valence
Stark effect
Raman scattering
pyrazines
Electric fields
Availability
Spectroscopy
Derivatives
availability
ethers
ions
assembly
asymmetry
Raman spectra
electric fields
symmetry
spectroscopy

Keywords

  • Delocalization
  • Electroabsorbance
  • Mixed-valence

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Spectroscopy
  • Atomic and Molecular Physics, and Optics

Cite this

Contrasting electroabsorbance behavior of two borderline class II/class III mixed-valence systems. / Dinolfo, Peter H.; Williams, Robert D.; Hupp, Joseph T.

In: Chemical Physics, Vol. 319, No. 1-3, 07.12.2005, p. 28-38.

Research output: Contribution to journalArticle

Dinolfo, Peter H. ; Williams, Robert D. ; Hupp, Joseph T. / Contrasting electroabsorbance behavior of two borderline class II/class III mixed-valence systems. In: Chemical Physics. 2005 ; Vol. 319, No. 1-3. pp. 28-38.
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