INVESTIGADORES
BERDAKIN Matias
artículos
Título:
The Effect of Ag+ on the Excited State Properties of Gas Phase (Cytosine)2Ag+ Complex: Electronic Transition and Estimated Lifetime
Autor/es:
M. BERDAKIN; G. FERAUD; C. DEDONDER-LARDEUX; C. JOUVET; G. A. PINO
Revista:
Journal of Physical Chemistry Letters
Editorial:
American Chemical Society
Referencias:
Lugar: Washington; Año: 2014 vol. 5 p. 2295 - 2301
ISSN:
1948-7185
Resumen:
Recently, DNA molecules have received great attention because of their potential applications in material science. One interesting example is the production of highly fluorescent and tunable DNA-Agn clusters. The formation of these fluorescent DNA-Agn clusters is favored when using cytosine (C) rich DNA strands. Here, we report the UV photofragmentation spectra of gas phase Cytosine?Ag+?Cytosine (C2Ag+) complex and compared the results with those of the Cytosine?H+?Cytosine (C2H+) complex. In both cases the excitation energy does not differ significantly from that of isolated cytosine or protonated-cytosine indicating that the excitation takes place on the DNA base. However, the excited state lifetime of the C2H+ ( = 85 fs), estimated from the bandwidth of the spectrum, is at least two orders of magnitude shorter than that of the C2Ag+ ( > 5300 fs). Ab-initio calculations show that this difference is due to the different relative positions of the locally excited * state and the low lying n* states that preclude the fast deactivation in C2Ag+.