TD DFT CALCULATIONS OF DNA BASE ION RADICAL EXCITED STATES

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 我们的NIH资助项目(RO1CA045424)的目标之一是使用密度泛函理论来阐明辐射损伤过程，包括离子自由基和激发态在这些机制中的作用。我们的项目目前正在利用含时密度泛函理论(TD-DFT)研究激发态在电子和空穴诱导的DNA损伤中的作用，如链断裂形成和糖自由基形成。理论被用来解释我们的实验结果。近期出版：1.综述一章：DFT处理DNA模型系统中辐射产生的自由基，李喜峰和Michael D.Sevilla，辐射与生物系统相互作用的理论处理一章。J.R.Sabin和E.Brandas主编，《量子化学进展》，Elsevier，第52卷，第59-88页(2007)。2.二核苷自由基阳离子的光激发：含时密度泛函研究。化学。低能电子诱导核苷中的碱基释放：密度泛函理论研究X.Li，L.Sanche和M.D.Sevilla，辐射研究，2006年，165721-729。4.鸟嘌呤正离子自由基：ESR和DFT对去质子态的研究A.Adhikary，A.Kumar，D.Becker，M.D.Sevilla，J.Phys.化学。2006年；第110(47)号；24171-24180。5.低能电子与5‘-胸腺嘧啶核苷单磷酸的连接：单链断裂模型突破解离电子连接；化学。B，111(19)，5464-5474,2007。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Our NIH funded project (RO1 CA045424) has as one of its aims to employ DFT theory to elucidate radiation damage processes including the role of ion radicals and excited states in these mechanisms. Our project is now investigating the role of excited states in electron and hole induced DNA damage such as strand break formation and sugar radical formation via the use of time-dependent density functional theory(TD-DFT). Theoy is employed to elucidate our experimental results. Recent publications: 1. Review Chapter: DFT Treatment of Radiation Produced Radicals in DNA Model Systems Xifeng Li and Michael D. Sevilla, Chapter in Theoretical Treatment of the Interaction of Radiation with Biological Systems. J. R. Sabin and E. Brandas, Eds., Advances in Quantum Chemistry, Elsevier, Volume 52, 59-88 (2007). 2. Photoexcitation of Dinucleoside Radical Cations: A Time-Dependent Density Functional Study A. Kumar, M. D. Sevilla J. Phys. Chem. B.; 2006; 110(47); 24181-24188 3. Base Release in Nucleosides Induced by Low-Energy Electrons: A DFT Study X. Li, L. Sanche and M. D. Sevilla, Radiation Research, 2006, 165, 721-729. 4. The Guanine Cation Radical: Investigation of Deprotonation States by ESR and DFT A. Adhikary, A. Kumar, D. Becker, M. D. Sevilla, J. Phys. Chem. B.; 2006; 110(47); 24171-24180. 5. Low-Energy Electron Attachment to 5'-Thymidine Monophosphate: Modeling Single Strand Breaks Through Dissociative Electron Attachment Kumar, A.; Sevilla, M. D. J. Phys. Chem. B, 111 (19), 5464 -5474, 2007.