title: FTIR studies of iron-carbonyl intermediates in allylic alcohol photoisomerization.
abstract: The 532 or 355 nm laser-induced photoisomerization of allylic alcohols to aldehydes catalyzed by [Fe(3)(CO)(12)] or [Fe(CO)(4)PPh(3)] in hexane was investigated. The Fourier transform infrared (FTIR) absorption spectra of iron-carbonyl intermediate species such as [Fe(CO)(5)], [Fe(CO)(4)(R-C(3)H(4)OH)], and more importantly the pi-allyl iron-carbonyl hydride species [FeH(CO)(3)(R-C(3)H(3)OH)] (R=H, Me, Ph) were recorded during the catalytic process using [Fe(3)(CO)(12)] as the catalytic precursor. When [Fe(CO)(4)PPh(3)] was photolyzed with 355 nm, [FeH(CO)(3)(R-C(3)H(3)OH)] was also generated indicating the common occurrence of the species in these two systems. The pi-allyl hydride species is long believed to be a key intermediates and its detection here lends support to the pi-allyl mechanism of the photoisomerization of allyl alcohols.
authors.affiliation: Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore.
authors.forename: Thiam Seong
authors.initials: TS
authors.lastname: Chong
authors.forename: Sze Tat
authors.initials: ST
authors.lastname: Tan
authors.forename: Wai Yip
authors.initials: WY
authors.lastname: Fan