Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
J Phys Chem Lett. 2021 Oct 28;12(42):10380-10387. doi: 10.1021/acs.jpclett.1c02735. Epub 2021 Oct 20.
We report a new doorway mechanism for the dissociative electron attachment to genetic materials. The dipole-bound state of the nucleotide anion acts as the doorway for electron capture in the genetic material. The electron gets subsequently transferred to a dissociative σ*-type anionic state localized on a sugar-phosphate or a sugar-nucleobase bond, leading to their cleavage. The electron transfer is mediated by the mixing of electronic and nuclear degrees of freedom. The cleavage rate of the sugar-phosphate bond predicted by this new mechanism is higher than that of the sugar-nucleobase bond breaking, and both processes are considerably slower than the formation of a stable valence-bound anion. The new mechanism can explain the relative rates of electron attachment induced bond cleavages in genetic materials.
我们报道了一种新的门控机制，用于遗传物质的电子离域。核苷酸阴离子的偶极束缚态充当了遗传物质中电子俘获的门控。电子随后转移到糖磷酸或糖-碱基键上的局域化的离域σ*-型阴离子态，导致它们的断裂。电子转移是通过电子和核自由度的混合来介导的。通过这个新机制预测的糖磷酸键的断裂速率高于糖碱基键的断裂速率，并且这两个过程都比形成稳定的价电子束缚阴离子慢得多。新机制可以解释遗传物质中电子附着诱导键断裂的相对速率。
