| Full text | |
| Author(s): |
Vivas, M. G.
;
Germino, J. C.
;
Barboza, C. A.
;
Simon, Deborah de A.
;
Vazquez, P. A. M.
;
De Boni, L.
;
Atvars, T. D. Z.
;
Mendonca, C. R.
Total Authors: 8
|
| Document type: | Journal article |
| Source: | Journal of Physical Chemistry C; v. 121, n. 2, p. 1283-1290, JAN 19 2017. |
| Web of Science Citations: | 11 |
| Abstract | |
Excited state intramolecular proton transfer (ESIPT) in a novel salicylidene sal-3,4-benzophen chromophore is studied by white-light femtosecond pumpprobe and time-resolved fluorescence techniques, as well as by theoretical calculations under the time dependent density functional theory framework. We show that when the sal-3,4-benzophen chromophore (in enol form) is excited (at 390 nm) to the cis-enol{*} form, it is quickly converted to the hot cis-keto{*} (hK{*}) form due to the fast ESIPT process (tau(ESIPT) = 150 fs). Subsequently, cooling from the hot cis-keto{*} (hK{*}) to cold cis-keto{*} (cK{*}) state takes place with a characteristic time constant of similar to 600 fs, with following relaxation decay time of 37 ps related with the photodynamic from sal-3,4-benzophen due to the occurrence of the cis -> trans photoisomerization and intersystem crossing mechanisms. Finally, we observed the fluorescence emission from the cis-keto{*} at 575 nm. The dynamics of the optical process was modeled using rate equations with the proper energy level diagram and supported by theoretical calculations. (AU) | |
| FAPESP's process: | 09/51602-5 - Chemical biology: new natural and synthetic molecular targets against cancer, structural studies, biological evaluation and mode of action |
| Grantee: | Ronaldo Aloise Pilli |
| Support Opportunities: | Research Projects - Thematic Grants |
| FAPESP's process: | 11/12399-0 - Femtosecond pulses applied to nonlinear optics: spectroscopy, pulse shaping and microfabrication |
| Grantee: | Cleber Renato Mendonça |
| Support Opportunities: | Research Projects - Thematic Grants |
| FAPESP's process: | 13/16245-2 - Photophysical properties of thin films of conjugated polymers |
| Grantee: | Teresa Dib Zambon Atvars |
| Support Opportunities: | Regular Research Grants |