Denifl Stephan, Zappa Fabio, Mähr Ingo, Lecointre Julien, Probst Michael, Märk Tilmann D, Scheier Paul
Institut für Ionenphysik und Angewandte Physik and Center for Molecular Biosciences Innsbruck, Leopold Franzens Universität Innsbruck, Technikerstrasse 25, A-6020 Innsbruck, Austria.
Phys Rev Lett. 2006 Jul 28;97(4):043201. doi: 10.1103/PhysRevLett.97.043201. Epub 2006 Jul 26.
Here we report the first mass spectrometric study of negative ions formed via free electron attachment (EA) to nucleobases (NBs) embedded in helium clusters. Pure and mixed clusters of adenine and thymine have been formed by pickup of isolated NB molecules by cold helium droplets. In contrast to EA of isolated molecules in the gas phase we observe a long-lived parent anion NB- and, in addition, parent cluster ions NB-n up to size n=6. Moreover, we show that a low energy electron penetrating into a doped helium droplet causes efficient damage of the embedded nucleobases via resonant, site selective, dissociative electron attachment.
在此，我们报告了首个通过自由电子附着（EA）到嵌入氦团簇中的核碱基（NBs）形成负离子的质谱研究。腺嘌呤和胸腺嘧啶的纯团簇和混合团簇是通过冷氦滴拾取孤立的NB分子形成的。与气相中孤立分子的EA不同，我们观察到一个长寿命的母体阴离子NB⁻，此外，还有尺寸达n = 6的母体团簇离子NBₙ。而且，我们表明，低能电子穿透掺杂的氦滴会通过共振、位点选择性、解离电子附着对嵌入的核碱基造成有效损伤。
