Effect of Ag+ on the Excited State Properties of Gas Phase (Cytosine)2Ag+ Complex: Electronic Transition and Estimated Lifetime

M. BERDAKÍN; G. FÉRAUD; C. DEDONDER-LARDEUX; C. JOUVET; G. A. PINO *

The Journal of Physical Chemistry Letters

American Chemical Society

Año: 2014 vol. 5 p. 2295 - 2295

1948-7185

ecently, 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 with cytosine (C)-rich DNA strands. Here, we report the UV photofragmentation spectra of gas-phase cytosine···Ag+···cytosine (C2Ag+) and cytosine···H+···cytosine (C2H+) complexes together with theoretical calculations. 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+ (τ = 85 fs), estimated from the bandwidth of the spectrum, is at least 2 orders of magnitude shorter than that of the C2Ag+ (τ > 5000 fs). The increased excited-state lifetime upon silver