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• The PECs of the 6 Λ-S states have been calculated. • The PECs of the 11 Ω states arising from 6 Λ-S states have been calculated. • TDM of spin forbidden transition from different multiplicity were investigated. • Interference of the intermediate a ʹ3Σ+ on direct laser cooling has been studied. High-level ab initio calculation of silver hydride (AgH) is performed by utilizing the internally contracted multi-reference configuration interaction plus Davidson correction method. A total of 6 Λ-S states and 11 Ω states from low-lying electronic states are computed in consideration of the spin-orbit coupling (SOC). The spectroscopic constants of bound states are determined and are in good agreement with the results of the available literature. A large aug-cc-pwCV5Z-PP basis set for Ag atom is applied during the calculations. The transition dipole moment (TDM) of spin forbidden transition between different multiplicity, caused by SOC effect, are computed based on Breit-Pauli operator. Particularly, the TDM of spin forbidden transitions between triplet a ʹ3Σ+, a 3Π, b ʹ3Σ+ and singlet X 1Σ+, A 1Σ+, C 1Π is studied and discussed. Finally, the interference of laser directly cooling by intermediate a ʹ3Σ+ states due to SOC was investigated based on the obtained TDM parameters. It proves that the perturbation from a ʹ3Σ+ state could be neglected in the laser cooling process. [ABSTRACT FROM AUTHOR]

The photoionization and dissociation of ethyl acrylate have been investigated by time-of-flight mass spectrometer with tunable vacuum ultraviolet (VUV) source in the range of 9.0–20.0 eV. The photoionization mass spectrum (PIMS) for ethyl acrylate and photoionization efficiency (PIE) curves for its major fragment ions: C 5 H 7 O 2 + , C 4 H 5 O 2 + , C 3 H 5 O 2 + , C 3 H 4 O + , C 3 H 3 O + , C 2 H 5 O + , C 2 H 3 O + , C 2 H 5 + and C 2 H 4 + have been obtained. The formation channels of main fragments are predicted by Gaussian 09 program at G3B3 level and examined via their dissociation energies from experimental results. Based on our analysis, nine main dissociative photoionization channels are proposed: C 5 H 7 O 2 + + H, C 4 H 5 O 2 + + CH 3 , C 3 H 5 O 2 + + C 2 H 3 , C 3 H 4 O + + C 2 H 4 O, C 3 H 3 O + + C 2 H 5 O, C 2 H 5 O + + C 3 H 3 O, C 2 H 3 O + + C 3 H 5 O, C 2 H 5 + + C 3 H 3 O 2 , C 2 H 4 + + C 3 H 4 O 2 , respectively. The results of this work lead to a better understanding of photochemistry in the environment. [ABSTRACT FROM AUTHOR]

Highlights: [•] Ionization energy of the molecule is determined. [•] Appearance energies of main fragment ions are determined for the first time. [•] The mechanism of the dissociation procedure is studied. [•] Ring forming and H shift are found in the dissociation of parent ion. [ABSTRACT FROM AUTHOR]

Abstract: Photoionization and dissociation of p-nitrotoluene in a region of 8.5–16.0eV have been investigated by tunable vacuum ultraviolet (VUV) synchrotron radiation. The ionization energy (IE) of p-nitrotoluene and the appearance energies (AEs) for major fragments, C7H7O+, , , , and , are determined respectively to be 9.54, 10.95, 11.46, 11.04, 12.45, and 14.25eV, by measurements of photoionization efficiency (PIE) curves. Five dissociative photoionization channels are proposed: C7H7O+ +NO, +NO2, +NO+CO, +NO+CO+H2, and +C2H2 +NO2. Additionally, the possible formation ways for the major fragments are predicted by ab initio calculations at G3B3 level and compared with the experimental results. All of these channels occur via isomerization prior to dissociation except for +NO2. Transition structures and intermediates for those isomerization are also determined in this work. [Copyright &y& Elsevier]