POLYEN PHOTOPHYSICS--RESONANCE RAMAN INTENSITY STUDIES

紫外共振拉曼光谱、激发轮廓和 将测量1，3-丁二烯、反式-丁二烯的绝对横截面。 蒸气和溶液中的1，3，5-己三烯和反式-1，3-戊二烯 阶段。气相共振拉曼光谱和吸收光谱 将被分析以绘制出激发态势能面 对于这些聚酯，特别是对于平面外 扭曲。绝对横截面将允许量化 垂直激发电子态的衰变速率， 而扭转模中的拉曼强度将揭示 围绕双键扭曲对这一利率的贡献。 延长到解决方案阶段将量化 激发态势面上的环境和 这些多烯中的非辐射衰减率以及 电子吸收光谱的不均匀展宽。 这些小多聚体是最简单的模型体系 具有重要生物学意义的多烯醛，视网膜。准确 关于它们的激发态势表面的知识和 光物理学，在分离的分子和溶液中都是 对于发展描述顺式反式基因的理论很重要 含有视网膜的视觉色素的光异构化和 细菌视紫红质。

Ultraviolet resonance Raman spectra, excitation profiles, and absolute cross sections will be measured for 1,3-butadiene, trans- 1,3,5-hexatriene, and trans-1,3-pentadiene in vapor and solution phases. The vapor phase resonance Raman and absorption spectra will be analyzed to map out the excited state potential surfaces for these polyeners, particularly with regard to out of plane distortions. The absolute cross sections will permit quantitation of the rate at which the verticall excited electronic state decays, while the Raman intensities in torsional modes will reveal the contribution to this rate from twisting around double bonds. Extension to the solution phase will quantitate the effect of an environment on the excited state potential surfaces and nonradiative decay rates in these polyenes as well as the amount of inhomogeneous broadening of the electronic absorption spectra. These small polyeners are the simplest model systems for the biologically important polyene aldehyde, retinal. Accurate knowledge of their excited state potential surfaces and photophysics, both in the isolated molecules and in solution is important for developing theories to describe cis-trans photoisomerization of the retinal-containing visual pigments and bacteriorhodopsin.