Electron Attachment to Uracil, Thymine and Cytosine
Electron Attachment to Uracil, Thymine and Cytosine
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电子与尿嘧啶、胸腺嘧啶和胞嘧啶的结合
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
T. D. Mrk
中科院分区：
文献类型：
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作者：
S. Denifl;S. Ptasińska;G. Hanel;B. Gstir;P. Scheier;M. Probst;B. Farizon;M. Farizon;Š. Matejčík;E. Illenberger;T. D. Mrk
Electron attachment (EA) to uracil (U), thymine (T) and cytosine (C) was studied in the electron energy range from about 0 to 12 eV using a high resolution crossed electron/molecule beams technique. The dominant negative ions formed via EA reactions to U, T and C are (U - H)-, (T - H)- and (C - H)-. The respective partial EA cross sections could be determined yielding peak values of σ(1.0 eV) = 3 × 10-20 m2, σ(1.05 eV) = 1.2 × 10-19 m2, σ(1.54 eV) = 2.3 × 10-20 m2, respectively. Based on (i) a comparison of the resonance positions for the different bases and on (ii) high level ab initio calculations we can assign certain resonances to the site specific loss of hydrogen during the EA reaction. At higher electron energies, in the range between about 3 and 12 eV we observe further product anions (e.g., for U the ions CN-, OCN- and C3H2NO-), however, with significantly lower cross section values.
