title: Photodissociation dynamics of indole in a molecular beam.
abstract: Photodissociation of indole at 193 and 248 nm under collision-free conditions has been studied in separate experiments using multimass ion imaging techniques. H atom elimination was found to be the only dissociation channel at both wavelengths. The photofragment translational energy distribution obtained at 193 nm contains a fast and a slow component. Fifty-four percent of indole following the 193 nm photoexcitation dissociate from electronically excited state, resulting in the fast component. The rest of 46% indole dissociate through the ground electronic state, giving rise to the slow component. A dissociation rate of 6 x 10(5) s(-1), corresponding to the dissociation from the ground electronic state, was determined. Similar two-component translational energy distribution was observed at 248 nm. However, more than 80% of indole dissociate from electronically excited state after the absorption of 248 nm photons. A comparison with the potential energy surfaces from the ab initio calculation has been made.
authors.affiliation: Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei 10617, Taiwan.
authors.forename: Ming-Fu
authors.initials: MF
authors.lastname: Lin
authors.forename: Chien-Ming
authors.initials: CM
authors.lastname: Tseng
authors.forename: Yuan T
authors.initials: YT
authors.lastname: Lee
authors.forename: Chi-Kung
authors.initials: CK
authors.lastname: Ni
mesh_terms: D000596:Amino Acids / Q000737:chemistry; D001482:Base Composition; D002627:Chemistry, Physical / Q000379:methods*; D004583:Electrons; D006859:Hydrogen / Q000737:chemistry*; D007211:Indoles / Q000737:chemistry*; D007477:Ions; D008027:Light; D008968:Molecular Conformation; D010777:Photochemistry / Q000379:methods*; D011522:Protons; D013050:Spectrometry, Fluorescence / Q000379:methods; D013056:Spectrophotometry, Ultraviolet; D013997:Time Factors; D014364:Tryptophan / Q000737:chemistry
chemical_list: D000596:Amino Acids; D007211:Indoles; D007477:Ions; D011522:Protons; D006859:Hydrogen; C030374:indole; D014364:Tryptophan