title: Formation of hydroxyl radical from the photolysis of salicylic acid.
abstract: Photodissociation dynamics of salicylic acid (SA) in the gas phase at different photolysis wavelengths (266, 315-317 nm) is investigated by probing the nascent OH photoproduct employing the single-photon laser-induced fluorescence (LIF) technique. At all the photolysis wavelengths it is found that the nascent OH radicals are produced mostly in a vibrationally ground state (υ'' = 0) and have similar rotational state distributions. The two spin-orbit and Λ-doublet states of the OH fragment formed in the dissociation are measured to have a nonstatistical distribution at each photolysis wavelength. The LIF signal of the OH could be observed upon photolysis at 317 nm but not at 317.5 nm. The threshold of OH formation from SA photodissociation is estimated to be 98.2 ± 0.9 kcal/mol. The effect of the phenolic OH group on the dissociation of SA is discussed.
authors.affiliation: State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China.
authors.forename: Can-Hua
authors.initials: CH
authors.lastname: Zhou
authors.forename: Shi-Bo
authors.initials: SB
authors.lastname: Cheng
authors.forename: Hong-Ming
authors.initials: HM
authors.lastname: Yin
authors.forename: Guo-Zhong
authors.initials: GZ
authors.lastname: He
mesh_terms: D017665:Hydroxyl Radical / Q000737:chemistry*; D055668:Photochemical Processes; D010782:Photolysis; D020156:Salicylic Acid / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D017665:Hydroxyl Radical; D020156:Salicylic Acid