Electroabsorption and related spectroscopic studies of bimetallic tetraiminoethylenedimacrocyclic complexes: Corroboration of valence electron delocalization
- Northwestern Univ., Evanston, IL (United States). Dept. of Chemistry
- Univ. of the Pacific, Stockton, CA (United States). Dept. of Chemistry
Mixed-valence complexes (chemical species containing multiple metal centers that exist formally in more than one oxidation state) represent ideal models for testing and understanding optical and thermal electron transfer. Though the prototypical mixed-valence ion, the Creutz-Taube ion, was first studied over 25 years ago, new mixed-valence complexes continue to be made and studied. Among the more interesting of these new complexes are a series of bimetallic tetraiminoethylenediamacro cycles (M{sub 2}TIEDL{sub 4}, where L is CH{sub 3}CN, dimethylformamide (DMF), or Cl{sup {minus}}, and M is Fe or Ru) 1. Electroabsorption spectroscopy directly measures the absolute difference in dipole moment ({vert_bar}{Delta}{mu}{vert_bar}) between a ground electronic state and a specified excited state. In this study, the authors report that intervalence excitation of the mixed-valent, diruthenium form of 1 is accompanied by essentially no change in molecular dipole moment, consistent with the previous description of the system as a fully delocalized assembly. The authors additionally performed near-infrared resonance Raman experiments with isovalent and mixed-valent diiron species. The results of these experiments provide further support for a delocalized mixed-valence ion description; they also provide some insight into the apparent mechanism for electronic delocalization.
- Sponsoring Organization:
- USDOE, Washington, DC (United States); National Science Foundation, Washington, DC (United States); Petroleum Research Fund (United States)
- DOE Contract Number:
- FG02-87ER13808; AC03-76SF00098
- OSTI ID:
- 642398
- Journal Information:
- Inorganic Chemistry, Journal Name: Inorganic Chemistry Journal Issue: 11 Vol. 37; ISSN 0020-1669; ISSN INOCAJ
- Country of Publication:
- United States
- Language:
- English
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