title: Charge-Transfer Complexes and Photochemistry of Ozone with Ferrocene and n-Butylferrocene: A UV-vis Matrix-Isolation Study.
abstract: The reactions of ozone with ferrocene (cp2Fe) and with n-butylferrocene (n-butyl cp2Fe) were studied using matrix isolation, UV-vis spectroscopy, and theoretical calculations. The codeposition of cp2Fe with O3 and of n-butyl cp2Fe with O3 into an argon matrix led to the production of 1:1 charge-transfer complexes with absorptions at 765 and 815 nm, respectively. These absorptions contribute to the green matrix color observed upon initial deposition. The charge-transfer complexes underwent photochemical reactions upon irradiation with red light (λ ≥ 600 nm). Theoretical UV-vis spectra of the charge-transfer complexes and photochemical products were calculated using TD-DFT at the B3LYP/6-311G++(d,2p) level of theory. The calculated UV-vis spectra were in good agreement with the experimental results. MO analysis of these long-wavelength transitions showed them to be n→ π* on the ozone subunit in the complex and indicated that the formation of the charge-transfer complex between ozone and cp2Fe or n-butyl cp2Fe affects how readily the π* orbital on O3 is populated when red light (λ ≥ 600 nm) is absorbed. 1:1 complexes of cp2Fe and n-butyl cp2Fe with O2 were also observed experimentally and calculated theoretically. These results support and enhance previous infrared studies of the mechanism of photooxidation of ferrocene by ozone, a reaction that has considerable significance for the formation of iron oxide thin films for a range of applications.
authors.affiliation: Department of Chemistry, University of Cincinnati , P.O. Box 210172, Cincinnati, Ohio 45221-0172, United States.
authors.forename: Laura F
authors.initials: LF
authors.lastname: Pinelo
authors.affiliation: Department of Chemistry, University of Cincinnati , P.O. Box 210172, Cincinnati, Ohio 45221-0172, United States.
authors.forename: Roger W
authors.initials: RW
authors.lastname: Kugel
authors.affiliation: Department of Chemistry, University of Cincinnati , P.O. Box 210172, Cincinnati, Ohio 45221-0172, United States.
authors.forename: Bruce S
authors.initials: BS
authors.lastname: Ault