@misc{oai:repo.qst.go.jp:00076766, author = {Hirato, Misaki and Onizawa, Misato and Fujii, Kentaro and Baba, Yuji and Haga, Yoshinori and Shin-ichi, Wada and Yokoya, Akinari and Hirato, Misaki and Onizawa, Misato and Fujii, Kentaro and Yokoya, Akinari}, month = {Aug}, note = {PURPOSE/INTRODUCTION: It has been known that cells are highly radiosensitized when their genomic DNA incorporates bromine (Br) atoms. Sometime, this strong radiosensitization screened Auger effect externally induced by monochromatic X-rays with energy above Br K-edge. We were intended to understand the radiosensitization mechanism in terms of electronic properties. METHODS: We applied X-ray absorption near edge structure (XANES) menasument and X-ray photoemission spectroscopy (XPS) for Br-uracil (BrU) and two nucleotides, Br-deoxyuridine monophosphate and thymidine monophosphate. To examine the microscopic state number of these molecules, we further measured specific heat of single crystals of BrUand thymine under low temperature. RESULTS: Obtaned XANES spectra around phosphorus, oxygen, nitrogen and carbon K-edge show that, contrary to our initial expectation, levels of LUMO were common regardless of Br incorporation. Obtained XPS spectra indicate that the core levels are also not affected by Br. Using the heat capacities obtained around 25 K region, the state numbers were calculated. We found that the value of BrU was about 1.5 times larger than that of thymine, although there was little difference between the values at a lower temperature than 5 K. DISCUSSION/CONCLUSION: When taken together these evidences, we suggest that Br atom may not significantly contribute to the electronic states of the molecule, but the states related to the excitation of lattice vibrations (oscillation and rotation in the molecule). The phonon excitation by secondary low energy electrons (or OH radicals) generated around BrdU in genomic DNA might play an important role for DNA damage induction rather than electronic states of BrU., The 9th International Symposium on Physical, Molecular, Cellular, and Medical Aspects of Auger Processes}, title = {Electronic properties of DNA related molecules incorporating a bromine atom}, year = {2019} }