TWO-PHOTON STUDIES OF AMINO ACIDS AND NUCLEIC ACIDS

提供选择规则的双光子电子态光谱 利用与普通紫外可见光谱互补的方法进行了研究 芳香氨基酸的低电子单重态激发态， DNA碱基、核苷酸和DNA聚合物。模型芳香族体系的研究 为了形成牢固的理解桥梁而继续进行 取代芳烃和不太为人所知的吲哚、嘌呤 和嘧啶碱基。印度/S计算，重点是彻底 将应用基组、参数和几何效应的研究 每一次实验。长期目标是实现一个坚实的基础 借助过渡密度图，理解 这些系统的电子结构--一个享有类似程度的 给予简单取代苯类的信任。一些关注的焦点是 在色氨酸发色团中定位“La起源”的特定目的， 吲哚类化合物的单光子激光紫外偏振荧光实验 In蒸气和碳氢玻璃被提出支持平行双光子 实验。单光子荧光和双光子实验 单链和双链病毒DNA被提出，特别是为了看看 本征荧光依赖于超螺旋和蛋白质络合作用。 将观察到Z-DNA的本征荧光。

Two-photon electronic state spectroscopy which offers selection rules complementary to those of ordinary UV-visible spectroscopy is used to study the low lying electronic singlet excited states of aromatic amino acids, DNA bases, nucleotides and DNA polymers. Studies of model aromatic systems are continued for the purpose of forming a firm bridge of understanding between substituted aromatics and the less well-understood indoles, purines and pyrimidine bases. INDO/S calculations, with emphasis on thorough investigation of basis set, parameter and geometry effects, will be applied to each experiment. The long range goal is to attain a firmly based understanding, with the aid of transition density pictures, of the electronic structure of these systems -- one that enjoys a similar degree of trust given to simple substituted benzenes. Some focus is on the specific aim of locating the "La origin" in the tryptophan chromaphore, indole; one-photon laser UV polarized fluorescence experiments on indoles in vapor and hydrocarbon glass are proposed to support parallel two-photon experiments. One-photon fluorescence as well as two-photon experiments on one and two-stranded viral DNA's are proposed, especially to see if intrinsic fluorescence depends on supercoiling and protein complexation. The intrinsic fluorescence of Z-DNA will be observed.