气相吡啶分子S_1态的(2+3)偏振共振多光子电离谱研究

Study on S_1 State in Pyridine Gas by (2+3) PRMPI Spectra

利用气相吡啶分子分别在圆偏振光激发和线偏振光激发下的 (2 +3)偏振共振多光子电离(PRMPI)谱 ,对其第一激发态 (S1)上的振转结构进行了研究。在谱中观察到了呈双峰结构的电子振转跃迁谱带。分析表明 ,所有振动谱带均为 S1态上ν6a、ν10 a、ν12 、ν16b和ν17a以及基态上ν9a的混合频率谱带。指认吡啶ν17a 的 S1态频率为 6 70 cm-1,并认为在 S1态上ν17a 频率降低的原因与ν10 a 类似。

The rovibronic structure on the first electronic excited state (S 1) in gaseous pyridine was studied in its (2+3) polarization resonance multiphoton ionization (PRMPI) spectra excited by circularly and linearly polarized laser respectively. In the spectra, double peak rovibronic bands were mostly observed. The result indicates that all the vibronic bands were assigned to various mixed frequency bands of ν 6a , ν 10a , ν 12 , ν 16b and ν 17a in S 1 and ν 9a in S 0 It is assigned that the frequency of ν 17a in S 1 state is 670 cm -1 , and the ν 17a frequency decreasing in S 1state is attributed to the similar mechanism undergone by ν 10a .