Comparative absorption, electroabsorption and electrochemical studies of intervalence electron transfer and electronic coupling in cyanide-bridged bimetallic systems

Ancillary ligand effects

Fredrick W. Vance, Robert V. Slone, Charlotte L. Stern, Joseph T Hupp

Research output: Contribution to journalArticle

33 Citations (Scopus)

Abstract

Electroabsorption or Stark spectroscopy has been used to evaluate the systems (NC)5M(II)-CN-Ru(III)(NH3)5/1- and (NC)5M(II)-CN-Ru(III)(NH3)4py1-, where M(II)=Fe(II) or Ru(II). When a pyridine ligand is present in the axial position on the Ru(III) acceptor, the effective optical electron transfer distance - as measured by the change in dipole moment, |Δμ| - is increased by more than 35% relative to the ammine substituted counterpart. Comparison of the charge transfer distances to the crystal structure of Na[(CN)5Fe-CN-Ru(NH3)4py] · 6H2O reveals that the Stark derived distances are ~50% to ~90% of the geometric separation of the metal centers. The differences result in an upward revision in the Hush delocalization parameter, c(b)/2, and of the electronic coupling matrix element, H(ab), relative to those parameters obtained exclusively from electronic absorption measurements. The revised parameters are compared to those, which are obtained via electrochemical techniques and found to be in only fair agreement. We conclude that the absorption/electroabsorption analysis likely yields a more reliable set of mixing and coupling parameters. (C) 2000 Elsevier Science B.V.

Original languageEnglish
Pages (from-to)313-322
Number of pages10
JournalChemical Physics
Volume253
Issue number2-3
DOIs
Publication statusPublished - Mar 1 2000

Fingerprint

Cyanides
cyanides
electron transfer
Crystal structure
Ligands
ligands
crystal structure
Electrons
electronics
ammines
Dipole moment
Charge transfer
pyridines
dipole moments
Metals
charge transfer
Spectroscopy
matrices
metals
spectroscopy

ASJC Scopus subject areas

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

Cite this

Comparative absorption, electroabsorption and electrochemical studies of intervalence electron transfer and electronic coupling in cyanide-bridged bimetallic systems : Ancillary ligand effects. / Vance, Fredrick W.; Slone, Robert V.; Stern, Charlotte L.; Hupp, Joseph T.

In: Chemical Physics, Vol. 253, No. 2-3, 01.03.2000, p. 313-322.

Research output: Contribution to journalArticle

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