| Revista: | Quimica nova |
| Base de datos: | PERIÓDICA |
| Número de sistema: | 000313337 |
| ISSN: | 0100-4042 |
| Autors: | Coelho, Paulo J1 |
| Institucions: | 1Universidade de Tras-os-Montes e Alto Douro, Departamento de Quimica, Vila Real. Portugal |
| Any: | 2006 |
| Període: | Jun |
| Volum: | 29 |
| Número: | 3 |
| Paginació: | 607-610 |
| País: | Brasil |
| Idioma: | Portugués |
| Tipo de documento: | Artículo |
| Enfoque: | Experimental |
| Resumen en inglés | An easy experiment on the synthesis of 3,3-diphenyl-3H-naphtho[2,1-b]pyran and characterization of its photochromic behaviour is reported. Upon irradiation of an uncoloured toluene solution of 3,3-diphenyl-3H-naphtho[2,1-b]pyran with near UV light, an intense yellow colouration is produced due to the formation of two coloured open forms. When the irradiation source is removed the coloured open forms return to the uncoloured state. The analysis of the absorbance decay with time allows the determination of the discoloration rate constants of each open form. The reversibility of the photochromic phenomenon, well demonstrated by the exposure of the solution to sunlight for a few seconds, is particularly attractive to the students |
| Disciplines | Química |
| Paraules clau: | Química orgánica, Educación química, Experimentos de laboratorio, Naftopirano, Espectrocinética, Fotocromismo |
| Keyword: | Chemistry, Organic chemistry, Chemical education, Laboratory experiments, Naphthopyran, Spectrokinetics, Photochromism |
| Text complet: | Texto completo (Ver HTML) |
