Dissociative ionization of allyl bromide in 800 nm and 400 nm intense femtosecond laser fields

doi:10.3969/j.issn.1000-5641.2019.03.012

Abstract

Abstract: Using a homemade time-of-flight mass spectrometer, the ionization and dissociation of gaseous molecular allyl bromide in 800 nm and 400 nm femtosecond laser fields were studied. By analyzing the dependence of ion fragment yields and laser intensity, combined with calculation of the Keldysh parameter, it was shown that multi-photon ionization dominates the ionization process involved in our experiment. Based on a theoretical calculation with the Gaussian 09 software package, flexible force constants and appearance energies of different fragment ions were calculated and dissociation channels were identified. Meanwhile, the results demonstrate that non-resonant multi-photon absorption will lead to simultaneous cleavage of multi-chemical bonds; moreover, the charge distribution of parent ions will steer the reaction pathway.

Key words: femtosecond laser, multiphoton dissociative ionization (MPDI), time-offlight mass spectrometry (TOF-MS), quantum chemistry calculation

CLC Number:

O431.1

LIU Yang, LIU Bo-tong, YANG Yan, SUN Zhen-rong. Dissociative ionization of allyl bromide in 800 nm and 400 nm intense femtosecond laser fields[J]. Journal of East China Normal University(Natural Sc, 2019, 2019(3): 110-119.

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