Study on the molecular structure of the photo induced phase in TTF-CA crystal by time-resolved Fourier transform infrared spectroscopy

研究了四硫富瓦烯对氯醌（TTF-CA）晶体在528 nm脉冲激光辐照下，在亚微秒时间范围内的傅里叶变换红外光谱的变化。 在TTF-CA块体晶体的时间分辨反射光谱中，发现CA分子的羰基伸缩振动引起的激发诱导反射峰出现在热平衡时离子相和中性相的不同位置。 瞬态反射峰是光诱导相CA分子的羰基伸缩振动。 光诱导相的电荷转移的程度被评估为0.5的瞬态峰的位置与具有不同的离子状态的CA分子的位置的比较。 用TTF-CA薄晶体的时间分辨红外吸收光谱测量再次证实了这些结果。

I have studied the change of Fourier transform infrared spectrum of tetrathiafulvalene-p-chloranil (TTF-CA) bulk and thin crystals induced by 528-nm pulsed laser irradiation in the sub-micro-seconds time range. In the time-resolved reflection spectroscopy with TTF-CA bulk crystal, I found that the excitation-induced reflection peak ascribed to the carbonyl-stretching vibration of CA molecules appears at the different position from ionic and neutral phases in thermal equilibrium. The transient reflection peak was concluded to the carbonyl stretching vibration of CA molecules in the photo-induced phase. The degree of charge transfer of the photo-induced phase was evaluated to be 0.5 by the comparison of the position of the transient peak with those of the CA molecules with distinct ionic states. These results were reconfirmed by the measurement of the time-resolved infrared absorption spectroscopy with TTF-CA thin crystals.