Picosecond time-resolved infrared absorption study on the electron-molecular vibration interactions of the dimers in the electronically excited states

1.构建时间分辨率约为3ps，光谱分辨率约为4cm ^<-1>的皮秒时间分辨红外吸收光谱仪。利用锁模掺铒光纤激光器（Clark-MXR CPA-2000）的二次谐波种子产生的皮秒级Ti：蓝宝石再生放大器的基频输出（波长775 nm，脉宽【近似等于】2.1 ps，重复率1 kHz）激发光参量发生器和放大器（Quantronix TOPAS）。在AgGaS_2晶体中，由光参量产生器和放大器产生的信号波和闲散波差频产生了波长为2500 nm ~ 11 μm （4000 ~ 900 cm^<-1>）的宽可调谐皮秒光脉冲。可调谐红外光脉冲的波数带宽【近似等于】16 cm^<-1>。我们使用色散光谱仪获得了【近似等于】4 cm^<-1>的光谱分辨率。多聚二聚体分子的合成及其激发态皮秒时间分辨红外吸收光谱的测量。我们合成了一些二聚体分子，并测量了它们在电子激发态下的皮秒时间分辨红外吸收光谱。基于分子轨道计算，对二聚体分子进行了结构优化和激发态振动分析。讨论了电子-分子振动相互作用。溶液中π共轭自由基阴离子和阴离子的红外吸收测量及基于密度泛函理论计算的光谱分析。对四氢呋喃溶液中萘、蒽、联苯和对苯基的阴离子和阴离子进行了高质量的红外光谱分析。观测到的红外光谱与密度泛函理论计算的结果吻合较好。从特定的正常振动（电子-分子振动相互作用）引起的电子结构变化的角度讨论了自由基阴离子和阴离子的强红外吸收强度特征的来源。少

1.Construction of a picosecond time-resolved infrared absorption spectrometer with time resolution of 【approximately equal】 3 ps and spectral resolution of 【approximately equal】 4 cm^<-1>.The fundamental output (wavelength 775 nm, pulse width 【approximately equal】 2.1 ps, repetition rate 1 kHz) from a picosecond Ti : sapphire regenerative amplifier seeded by the second harmonic of a mode-locked Er-doped fiber laser (Clark-MXR CPA-2000) was used to excite an optical parametric generator and amplifier (Quantronix TOPAS). Widely tunable picosecond light pulses in the 2500 nm - 11 μm (4000 - 900 cm^<-1>) range were obtained by difference-frequency generation in an AgGaS_2 crystal between the signal and idler waves from the optical parametric generator and amplifier. The wavenumber bandwidth of the tunable infrared light pulses was 【approximately equal】 16 cm^<-1>. We achieved the spectral resolution of 【approximately equal】 4 cm^<-1> by using a dispersive spectrometer.2.Syntheses of some d … More imer molecules and measurements of picosecond time-resolved infrared absorption spectra of their excited states.We synthesized some dimer molecules and measured the picosecond time-resolved infrared absorption spectra of them in the electronically excited states. Optimizations of molecular structures and vibrational analyses for the excited states of dimer molecules were performed based on molecular orbital calculations. The electron-molecular vibration interactions will be discussed.3.Infrared absorption measurements of π-conjugated radical anions and dianions in solution and spectral analyses based on density functional theory calculations.High-quality infrared spectra were observed for the radical anions and dianions of naphthalene, anthracene, biphenyl, and p-phenyl in tetrahydrofuran solutions. Observed infrared spectra were in good agreement with those calculated by density functional theory. The origin of the strong infrared absorption intensities characteristic of the radical anions and dianions were discussed in terms of changes in electronic structures induced by specific normal vibrations (electron-molecular vibration interaction). Less