title: Multiphoton ionization/dissociation dynamics of formyl fluoride by velocity mapping ion imaging.
abstract: The dissociation dynamics of HFCO(+) ion has been studied using the velocity map ion imaging technique. The HFCO(+) ion is prepared by one-photon resonant three-photon ionization in the region of 43100-43860 cm(-1) excitation energy. The HFCO(+) ions, produced by multiphoton ionization, have sufficient internal energy to dissociate into the F and HCO(+) fragments without further absorption of another photon. Images of HCO(+) have been recorded at various excitation energies. It is noticed that the angular distributions of HCO(+) change dramatically from parallel distribution to perpendicular distribution and then back to parallel distribution in a very narrow excitation energy region of 43 473-43 500 cm(-1). Analysis of anisotropy parameters of beta(n) (n = 2, 4 and 6) reveals that the electronic states in the three-photon excitation of HFCO are mainly: HFCO(X(1)A') --> HFCO(A(1)A'') --> HFCO(A') --> HFCO(+)(A(2)A'';B(2)A'). The purely perpendicular resonant transitions are likely responsible for the perpendicular angular distribution of the HCO(+) ion fragment.
authors.affiliation: State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, PR China.
authors.forename: Fengyan
authors.initials: F
authors.lastname: Wang
authors.forename: Yongwei
authors.initials: Y
authors.lastname: Zhang
authors.forename: Hua
authors.initials: H
authors.lastname: Wang
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.forename: Bo
authors.initials: B
authors.lastname: Jiang
authors.forename: Xiuyan
authors.initials: X
authors.lastname: Wang
authors.forename: Xueming
authors.initials: X
authors.lastname: Yang