Characterization of the low-energy electronic excited states of benzoyl-substituted ruthenocenes

Academic Article

Abstract

  • Electronic absorption and resonance Raman spectral studies of benzoylruthenocene (BRc) and 1,1′-dibenzoylruthenocene (DRc) indicate that the low-energy electronic excited states of these 4d 6 metallocenes possess metal-to-ligand charge transfer (MLCT) character. While this MLCT contribution should weaken the metal-ring bonding in the excited state, neither compound is photosensitive in nonhalogenated solvents such as methanol, acetonitrile, and cyclohexane. In contrast, irradiating BRc and DRc in the good electron-accepting solvent, carbon tetrachloride, results in ring loss via a pathway that appears to originate from a charge-transfer-to-solvent excited state. Both metallocenes function as photoinitiators for the anionic polymerization of ethyl 2-cyanoacrylate, and the kinetics and mechanism of this process have been investigated. Comparing the present results on BRc and DRc with those reported earlier for the corresponding benzoyl-substituted ferrocene compounds reveals some interesting commonalities and differences between the excited-state properties of these 3d and 4d metallocenes. © 2005 American Chemical Society.
  • Authors

    Digital Object Identifier (doi)

    Pubmed Id

  • 3159445
  • Author List

  • Sanderson CT; Quinlan JA; Conover RC; Johnson MK; Murphy M; Dluhy RA; Kutal C
  • Start Page

  • 3283
  • End Page

  • 3289
  • Volume

  • 44
  • Issue

  • 9