Electronic Structures of Purine Bases Studied by Electrochemical-ESR Techniques. Spin Distribution in Purine Anion Radical
作者:Hiroaki Ohya-Nishiguchi、Yasunori Shimizu、Noboru Hirota、Kohji Watanabe
DOI:10.1246/bcsj.53.1252
日期:1980.5
We have investigated the ESR spectrum of anion radical of purine generated electrochemically using a helical electrode cell for low-temperature ESR measurements. The assignment of the hfcc was made with the aid of partial deuteration and MO calculations. The most notable observation is that about 45% of the spin density is localized at position 6. This correlates well with the preferential hydrogenation
我们研究了使用螺旋电极电池电化学产生的嘌呤阴离子自由基的 ESR 谱,用于低温 ESR 测量。hfcc 的分配是在部分氘化和 MO 计算的帮助下进行的。最值得注意的观察结果是大约 45% 的自旋密度位于位置 6。这与该位置的优先氢化有很好的相关性。McLachlan 方法很好地再现了观察到的自旋分布,βN9C⁄βCC=1.0,这表明 9 处的氮与 4 和 8 处的碳之间的键具有较大的双键特征。基于 9H-嘌呤的两种分子几何结构的 INDO-MO 计算也与实验数据非常吻合。最后讨论了嘌呤互变异构对光谱的影响。