Shape resonance spectrum of cytosine-guanine pairs.


Autoria(s): Varella, Marcio Teixeira do Nascimento; Nunes, F. B.; Pastega, D. F.; Freitas, T. C. de; Bettega, M. H. F.; Sanchez, S. d'A.
Contribuinte(s)

UNIVERSIDADE DE SÃO PAULO

Data(s)

19/03/2014

19/03/2014

2013

Resumo

Single and double strand breaks in DNA can be caused by low-energy electrons, the most abundant secondary products of the interaction of ionizing radiation to the biological matter. Attachment of these electrons to biomolecules lead to the formation of transient negative ions (TNIs) [1], often referred to as resonances, a process that may lead to significant vibrational excitation and dissociation. In the present study, we employ the parallel version [2] of the Schwinger Multichannel Method implemented with pseudopotentials [3] to obtain the shape resonance spectrum of cytosine-guanine (CG) pairs, with special attention to π* transient anion states. Recent experimental studies pointed out a quasi-continuum vibrational excitation spectrum for electron collisions against formic acid dimers [4], suggesting that electron attachment into π* valence orbitals could induce proton transfer in these dimers. In addition, our previous studies on the shape resonance spectra of the hydrogen-bonded complexes comprising formic acid and formamide units indicated interesting electron delocalization (localization) effects arising from the presence (absence) of inversion symmetry centers in the complexes [5]. In the present work, we extend the studies on hydrogen-bonded complexes to the CG pair, where localization of ¼¤ anions would be expected, based on the previous results. References [1]. B. Boudaïffa, P. Cloutier, D. Hunting, M. A. Huels, L. Sanche, Science 287, 1658 (2000). [2]. J. S. dos Santos, R. F. da Costa , M. T. do N. Varella, J. Chem. Phys. 136, 084307 (2012). [3]. M. H. F. Bettega, L. G. Ferreira, M. A. P. Lima, Phys. Rev. A 47, 1111 (1993). [4]. M. Allan, Phys. Rev. Lett. 98, 123201 (2007). [5]. T. C. Freitas, S. dA. Sanchez, M. T. do N. Varella, M. H. F. Bettega, Phys. Rev. A 84, 062714 (2011).

CNPq

FAPESP

Fundação Araucária

Identificador

Encontro Nacional de Física da Matéria Condensada, XVIII, 2013, Aguas de Lindóia.

http://www.producao.usp.br/handle/BDPI/44209

http://www.sbf1.sbfisica.org.br/eventos/enfmc/xxxvi/sys/resumos/R0658-1.pdf

Idioma(s)

eng

Publicador

Sociedade Brasileira de Física

Águas de Lindóia

Relação

Encontro Nacional de Física da Matéria Condensada, 36

Direitos

openAccess

Márcio Teixeira do Nascimento Varella

Palavras-Chave #Cytosine-guanine pairs #Shape resonance spectrum #RESSONÂNCIA MAGNÉTICA
Tipo

conferenceObject