Photoreaction channels of the guanine-cytosine base pair explored by long-range corrected TDDFT calculations

• Yamazaki, Shohei

• Taketsugu, Tetsuya

抄録

Photoinduced processes in the Watson-Crick guanine-cytosine base pair are comprehensively studied by means of long-range corrected (LC) TDDFT calculations of potential energy profiles using the LC-BLYP and CAM-B3LYP functionals. The ab initio CC2 method and the conventional TDDFT method with the B3LYP functional are also employed to assess the reliability of the LC-TDDFT method. The present approach allows us to compare the potential energy profiles at the same computational level for excited-state reactions of the base pair, including single and double proton transfer between the bases and nonradiative decay via ring puckering in each base. In particular, long-range correction to the TDDFT method is critical for a qualitatively correct description of the proton transfer reactions. The calculated energy profiles exhibit low barriers for out-of-plane deformation of the guanine moiety in the locally-excited state, which is expected to lead to a conical intersection with the ground state, as well as for single proton transfer from guanine to cytosine with the well-known electron-driven proton transfer mechanism. Thus the present results suggest that both processes can compete in hydrogen-bonded base pairs and play a significant role in the mechanism of photostability.

収録刊行物

• Physical Chemistry Chemical Physics

  Physical Chemistry Chemical Physics 14 (25), 8866-8877, 2012-04-17

  Royal Society of Chemistry

キーワード

• Physical and Theoretical Chemistry
• General Physics and Astronomy

詳細情報

• CRID: 1050845763940944640
• NII論文ID: 120005323590
• DOI: 10.1039/c2cp23867e
• ISSN: 14639084
• ISSN: 14639076
• HANDLE: 2115/53176
• Web Site: http://pubs.rsc.org/en/content/articlepdf/2012/CP/C2CP23867E
• 本文言語コード: en
• 資料種別: journal article
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