Photochemistry of deca(acetonitrile) dirhodium(II) cation: evidence for kilosecond-lived photoinduced charge separation Academic Article uri icon


  • Events following the photodissociation of the dinuclear rhodium(II,II) complex Rh2L10 (L = CH3CN), are reported. Spectroscopic and electrochemical evidence demonstrates that this complex possesses novel reversible photochemistry with metastable photoproducts that exist for kiloseconds after photodissociation, and ultimately regenerate the original dimer. UV/Vis irradiation of acetonitrile solutions of the complex results in homolytic cleavage of the Rh-Rh bond to give a promptly formed paramagnetic transient that EPR evidence suggests to be Rh(II)L6. This species has a half-life of ca. 50 s, and initiates a reaction sequence that generates photodisproportionated, metastable products, which are inferred to be Rh(III)L6 and Rh3(II,II,I)Ln These products have half-lives in the kilosecond range. The proposed photochemical processes thus achieve photoinduced charge separation, with remarkably long lifetimes for the charge-separated species. The metastable species may be viewed as a photogenerated electron-hole pair in solution that, due to its long lifetimes, may have significant potential in converting light into usable chemical energy.

author list (cited authors)

  • James, C. A., Morris, D. E., Doorna, S. K., Arrington, C. A., Dunbar, K. R., Finnis, G. M., Pence, L. E., & Woodruff, W. H.

citation count

  • 12

publication date

  • February 1996