title: Photodissociation dynamics of tryptophan and the implication of asymmetric photolysis.
abstract: Photodissociation of amino acid tryptophan in a molecular beam at wavelengths of 212.8 and 193 nm, corresponding to excitation to the second and third absorption bands, was investigated using multimass ion imaging techniques. The respective wavelengths also represent excitation to the edge of a positive circular dichroism band and the center of a negative circular dichroism band of L-tryptophan. Only one dissociation channel was observed at both photolysis wavelengths: C(8)NH(6)CH(2)CHNH(2)COOH-->C(8)NH(6)CH(2)+CHNH(2)COOH. Dissociation rates were found to be 1.3x10(6) and 5x10(6) s(-1) at the respective wavelengths. Comparison to theoretical calculation indicates that dissociation occurs on the ground state after internal conversion. Implication of asymmetric photolysis is discussed.
authors: Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan.
authors: Chien-Ming
authors: CM
authors: Tseng
authors: Yuri A
authors: YA
authors: Dyakov
authors: Huai Ching
authors: HC
authors: Huang
authors: Kuan Yu
authors: KY
authors: Huang
authors: Yuan T
authors: YT
authors: Lee
authors: Chi-Kung
authors: CK
authors: Ni
authors: Su-Yu
authors: SY
authors: Chiang
mesh_terms: D004583:Electrons; D007700:Kinetics; D010782:Photolysis; D013816:Thermodynamics; D014364:Tryptophan / Q000737:chemistry*
chemical_list: D014364:Tryptophan