Berlin 2015 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 25: Posters: DNA/RNA and related enzymes
BP 25.2: Poster
Dienstag, 17. März 2015, 14:00–16:00, Poster A
Ultrafast energy dissipation within the vibrational modes of the DNA backbone — •Yingliang Liu, Biswajit Guchhait, Rene Costard, Torsten Siebert, and Thomas Elsaesser — Max-Born-Institut für Nichtlinear Opitk und Kurzzeitspektroskopie, Max-Born-Str. 2a, 12489 Berlin, Germany
The long-term stability of the DNA helix structure requires efficient processes of electronic and vibrational relaxation as well as energy dissipation into an aqueous environment. To determine the relevant time-scales and pathways of relaxation, femtosecond pump-probe experiments on artificial double-stranded DNA oligomers are performed under conditions of full hydration. Specifically addressing the structure of the DNA backbone in the frequency range from 950 to 1300 cm−1, the vibrational modes of the phosphate group, phosphodiester linkage and the furanose ring structure display subpico- to picosecond lifetimes. While excess energy released by the relaxation of phosphate vibrations is preferentially transferred into the surrounding water shell, clear signatures of vibrational energy transfer to the modes of the sugar linkage and ring structure are observed and these channels of energy dissipation are compared for different hydration levels.