用位相失匹配CARS方法研究尿嘧啶核苷分子的振动结构

Study of the Vibrational Structure of Uridine in Aqueous Solution by Phase-mismatched CARS

在９００～１５００ｃｍ－１波段范围内，检测了尿嘧啶核苷水溶液的ＣＡＲＳ谱。由于采用了位相失匹配方法，从而消除了非共振背景，由此确定了碱基环骨架振动的若干模式，以及Ｃ—Ｈ键和Ｎ—Ｈ键的弯曲振动模式，侧链糖环的弱振动模式也可以在谱中观察到。对失匹配方法的原理及其实验条件给予了讨论。

CARS spectra of Uridine in aqueous solution are examined in the region of 900～1500 cm-1. The nonresonant background has been remarkably suppressed by using a phase mismatching method. The ring skeletal stretching modes of base, C-H bending modes and N-H bending mode can be assigned unambiguously, and the very weak vibrational modes of ribose are also oberved. The experimental conditions of the phase mismatching technique are discussed with a numerical calculation. We conclude that background-eliminated CARS measurement is a powerful tool for studying the structures of nucleic acids.