In this study, we employed a newly built time-slice velocity-map ion imaging setup, equipped with two tunable vacuum ultraviolet (VUV) laser sources, to obtain the first comprehensive high-resolution photoexcitation and photofragment excitation spectra of 14N15N in the VUV photon energy range 109 000–117 500 cm−1. The spectroscopic simulation program PGOPHER was used to analyze the rotationally resolved spectra. Band origins, rotational constants, and isotope shifts compared with those of 14N2 have been obtained for 31 electric-dipole-allowed vibrational states of 14N15N in the aforementioned energy range. These spectroscopic parameters are found to depend on the vibrational quantum number irregularly. Systematic perturbations of the rotational transition energies and predissociation rates within individual absorption bands have also been observed. These are proved to be caused by the strong homogeneous interactions between the valence b′1Σu+ state and the Rydberg 1Σu+ states, and between the valence b1Πu states and the Rydberg o31Πu states. Heterogeneous interactions between the Rydberg cn1Πu states and 1Σu+ states also play an important role.
Vacuum ultraviolet photoexcitation and photofragment spectroscopic studies of 14N15N between 109000 and 117500 cm−1
Note: This paper is part of the 2021 JCP Emerging Investigators Special Collection.
Min Liu, Pan Jiang, Min Cheng, Hong Gao; Vacuum ultraviolet photoexcitation and photofragment spectroscopic studies of 14N15N between 109000 and 117500 cm−1. J. Chem. Phys. 21 December 2021; 155 (23): 234305. https://doi.org/10.1063/5.0072604
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