Estudo teórico-computacional da transferência de próton na benzofenona-3

• Autor(a) principal: Oliveira, Jorgiano Souza
• Data de Publicação: 2013
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• dARK ID: ark:/38995/0013000006w42
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/9906
• topic: Benzofenona-3; ESIPT; DFT; TDDFT; Ultravioleta; Ultraviolet; FISICO-QUIMICA::QUIMICA TEORICA

Ultraviolet radiation from the sun is cited as the main cause of skin cancer. To protect of this kind of radiation, benzophenone-3 is used in many sunscreens, due it’s ability to dissipate ultraviolet energy. The process of this energy dissipation is through the me-chanism known as ESIPT, which a constitutes intramolecular transfer ultrafast proton to another functional group. We adopted semi-empirical methods AM1, PM3 and PM6; and DFT with different atomic basis sets. The calculations of the excited states were performed with the TDDFT. The results of the electronic structure found by several le-vels of calculations and the results of theoretical absorption spectra were compared with the data found in the literature. The dissipation mechanism can be explained building potencial energy curves and surfaces of the ground state and the excited states, showing the efficiency of the molecule to absorb and dissipate the frequency of ultraviolet radia-tion. Calculations and carried out for several derivatives of benzophenone-3, show that it is possible to change the absortions peak.