Chemical and Electrochemical Studies of Cl₂FeS₂MS₂FeCl₂^n- Clusters [M = Mo (n = 2), W (n = 2), V (n = 3)]

Authors

Yanming Liu, Marquette UniversityFollow
Jinhai Chen, Marquette UniversityFollow
Michael D. Ryan, Marquette UniversityFollow

Document Type

Article

Language

eng

Format of Original

7 p.

Publication Date

2-1-1998

Publisher

American Chemical Society

Source Publication

Inorganic Chemistry

Source ISSN

0020-1669

Abstract

The electrochemistry and spectroelectrochemistry of [Cl₂FeS₂MS₂FeCl₂]^n- clusters (where n = 2 for M = Mo and W and n = 3 for M = V; Ia, Ib, and Ic, respectively) and the dimetal complex [Cl₂FeS₂MoS₂]^2- (IIIa) were examined in order to characterize the structures and properties of the one-electron-reduced complexes. A stable reduction product for Ia was observed spectroelectrochemically at −1.05 V, which could be oxidized back to the starting complex. Reduction at more negative potentials caused complete bleaching of the spectrum, and the starting complex could not be obtained by reoxidation. Similar behavior was observed for the tungsten complex, Ib, but the dimetal complex [Cl₂FeS₂WS₂]^2- was formed upon reoxidation. Chemical and electrochemical reduction of Ia and Ib both led to the same products (IIa and IIb), but by different mechanisms. Borohydride reduction of Ia and Ib led to the initial formation of the dimetal complex, while the electrochemical reduction of Ia proceeded by way of the formation of [Cl₂FeS₂MoS₂FeCl₂]^3-. Spectral changes were observed in the reduction of Ic, but they were not reversible. Resonance Raman spectroscopy of the reduced complexes was carried out in order to characterize the reduction product. Two polarized bands in the sulfur bridging region were observed in the resonance Raman spectra of electrochemically and chemically generated IIa and IIb. The relative intensities of these bands were dependent upon the excitation frequency. Reduction of Ic led to the loss of all resonance Raman bands. Reduction of IIIa gave rise to a complex (IVa) that was spectrally quite similar to IIa. These results, along with the previously reported result that the reduction complex was diamagnetic, indicate that the complex IIa is a dimeric species. The most likely structure consistent with these data is a Mo₂Fe₂S₄ cubane structure.

Comments

Accepted version. Inorganic Chemistry, Vol. 37, No. 3 (February 1, 1998): 425-431. DOI. © 1998 American Chemical Society. Used with permission.

Recommended Citation

Liu, Yanming; Chen, Jinhai; and Ryan, Michael D., "Chemical and Electrochemical Studies of Cl₂FeS₂MS₂FeCl₂^n- Clusters [M = Mo (n = 2), W (n = 2), V (n = 3)]" (1998). Chemistry Faculty Research and Publications. 509.
https://epublications.marquette.edu/chem_fac/509