Absorption by DNA single strands of adenine isolated in vacuo: the role of multiple chromophores.
J Chem Phys
; 136(6): 064302, 2012 Feb 14.
Article
en En
| MEDLINE
| ID: mdl-22360182
The degree of electronic coupling between DNA bases is a topic being up for much debate. Here we report on the intrinsic electronic properties of isolated DNA strands in vacuo free of solvent, which is a good starting point for high-level excited states calculations. Action spectra of DNA single strands of adenine reveal sign of exciton coupling between stacked bases from blueshifted absorption bands (~3 nm) relative to that of the dAMP mononucleotide (one adenine base). The bands are blueshifted by about 10 nm compared to those of solvated strands, which is a shift similar to that for the adenine molecule and the dAMP mononucleotide. Desolvation has little effect on the bandwidth, which implies that inhomogenous broadening of the absorption bands in aqueous solution is of minor importance compared to, e.g., conformational disorder. Finally, at high photon energies, internal conversion competes with electron detachment since dissociation of the bare photoexcited ions on the microsecond time scale is measured.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
ADN de Cadena Simple
/
Adenina
Idioma:
En
Revista:
J Chem Phys
Año:
2012
Tipo del documento:
Article
País de afiliación:
Dinamarca
Pais de publicación:
Estados Unidos