%A ZHOU Dan-Na, CHEN Lin, WU Dan, ZHANG Li-Min
%T Photodissociation Spectra of OCS^{+} via *A*^{2}*П*←*X*^{2}*П* Transitions
%0 Journal Article
%D 2012
%J Acta Phys. -Chim. Sin.
%R 10.3866/PKU.WHXB201202162
%P 963-970
%V 28
%N 04
%U {http://www.whxb.pku.edu.cn/CN/abstract/article_27966.shtml}
%8 2012-03-21
%X In the wavelength range 260-325 nm, we obtained mass-resolved dissociation spectra of OCS^{+} via *A*^{2}*П*_{3/2}←*X*^{2}*П*_{3/2} (000) and *A*^{2}*П*_{1/2}←*X*^{2}*П*_{1/2} (000, 001) transitions by preparing OCS^{+} (*X*^{2}*П*) ions via [3+1] resonance enhanced multiphoton ionization (REMPI) of OCS molecules at 423, 420, 412.2, and 408.4 nm. The mass-resolved dissociation spectra of OCS^{+} via *A*^{2}*П*_{1/2}←*X*^{2}*П*_{1/2} (001) were observed for the first time. The spectroscopic constants *T*_{0}=31411.3 cm^{-1} and *v*_{1}=814.3 cm^{-1} for the OCS^{+} (*A*^{2}*П*_{3/2}) state were deduced from the *A*^{2}*П*_{3/2}←*X*^{2}*П*_{3/2} (000) photodissociation spectra, and the spectroscopic constants *v*_{1}=816 cm^{-1}, *v*_{2}=(380.4± 2.8) cm^{-1}, and *v*_{3}=(2052.7±5.1) cm^{-1} for the OCS^{+} (*A*^{2}*П*_{1/2}) state were deduced from the *A*^{2}*П*_{1/2}←*X*^{2}*П*_{1/2} (000) spectra. The spectroscopic constant *v*_{1}=786.4 cm^{-1} was deduced from the *A*^{2}*П*_{1/2}←*X*^{2}*П*_{1/2} (001) photodissociation spectra. The results show that the C－O stretching mode excitation of *X*^{2}*П*_{1/2} can affect the C－S stretching mode vibration of the *A*^{2}*П*_{1/2} state via *A*^{2}*П*_{1/2}←*X*^{2}*П*_{1/2} (001) transitions. Bands involving the bending *v*_{2} mode excitation of A2П, such as *A*^{2}*П*_{1/2} (020, 120, 021, …), were observed for the *A*^{2}*П*_{1/2}←*X*^{2}*П*_{1/2} (000, 001) transitions, but were not observed for the *A*^{2}*П*_{3/2} (υ_{1}υ_{2}υ_{3}) ←*X*^{2}*П*_{3/2} (000) transitions in the photodissociation spectra. The reason for this dependence of the bending *v*_{2} mode excitation of *A*^{2}*П* on the spin-orbit splitting of the ^{2}*П* state can be attributed to the Fermi resonance and Renner-Teller effect of OCS^{+} (*A*^{2}*П*).