本文从拉曼峰强入手,求得了亚乙基硫脲(ETU)分子的“时间分辨键极化率”,并讨论了该分子的激发拉曼虚态性质,发现了该分子“激发虚态电子向分子外围键流动”、“电子弛豫后的键极化率分布与基态电子的密度分布相似”、“不同激发波长下的键极化率衰减时间满足不确定关系”等特点。本文还研究了该分子的表面增强拉曼光谱,指出“电荷转移机制”的极化率弛豫时间长于“电磁增强机制”等与表面增强拉曼效应相关的结论。
An algorithm is employed to elucidate molecular bond polarizabilities of ethylene thiourea(ETU) including their temporal relaxation from Raman intensities. The main character of the excited states of ETU is that the excited electrons tend to flow to the molecular periphery due to electronic repulsion. The bond electronic densities of the ground state can be mapped out by the bond polarizabilities at the final stage of relaxation and the relaxation time is shown to be proportional to the wavelength of the exciting light in agreement with Heisenberg' s uncertainty principle. We also research the surface enhanced Raman scattering (SERS) intensities of ETU on the silver electrode, and confirm that the life time for the relaxation due to charge transfer mechanism is larger than that via the electromagnetic mechanism.