TWO-PHOTON STUDIES OF AMINO ACIDS AND NUCLEIC ACIDS

双光子光谱学(TPS)，它提供互补的选择规则 对于普通的单光子光谱(OPS)，将应用于 首次研究低能级PI电子单重态激发态 芳香族氨基酸、DNA碱基、二核苷酸和DNA聚合物。在… 首先，偏振双光子荧光激发光谱将是 氮杂环己烷和氟代萘的新化合物。我们在寻找 这两个实验是对强大的理论方案的关键考验 它利用过渡密度矩阵和地图的图形来制作 关于相对单光子和双光子行为的确凿声明 环状多烯的两个最低等电点电子激发态 “微扰”的影响，如交联性和感应性 替换。用CNDO/S-CI进行计算并完成 过渡密度，一个主要的目标是找到DNA碱基的理论基础 电子结构与过去理解的结构更明确地联系在一起 更简单的系统。此外，单分子和双分子的荧光 高纯度的滞留病毒DNA将被调查，以及 超螺旋和多胺诱导的塌陷效应，这都是第一次 时间到了。双光子荧光激发光谱的比较 DNA和DNA-蛋白质将在单体和聚合物之间进行 复合体。

Two-photon spectroscopy (TPS), which offers selection rules complementary to those for ordinary one-photon spectroscopy (OPS), will be applied, for the first time, to study the low lying Pi electron singlet excited states of aromatic amino acids, DNA bases, dinucleotides, and DNA polymers. At the outset, polarized two-photon fluorescene excitation spectra will be obtained for aza and fluoronapthalenes for the first time. We seek from these latter experiments a critical test of a powerful theoretical scheme which makes graphic use of transition density matrices and maps to make definitive statements regarding relative one- and two-photon behavior of the two lowest Pi electron excited states of cyclic polyenes under the influence of "perturbations" such as cross-linking and inductive substitutions. With the use of CNDO/S-CI calculations and the complete transition densities, a major goal is to find a rationale for the DNA base electronic structure more explicitly linked to that used to understand simpler systems. Additionally, the fluorescence of single and double stranded viral DNA of high purity will be investigated, as well as the effect of supercoiling and polyamine induced collapse, all for the first time. Comparison of the two-photon fluorescence excitation spectrum between monomers and polymer will be carried out for DNA and DNA-protein complexes.