Estudos cinéticos de isatina e algumas cetonas aromáticas frente a novas fosforilidrazonas

Abstract

The present study has two specific phases: Early, was studied the isathine irradiation with the presence of diisopropil-phosphoril-dimethylidrazone (diisopfh), in chloroform, at room temperature and 300nm. The structure of photo-product was elucidated by GC/MS, IR, NMR 1H, 13C and 31P, as well as hety-cosy, homo-cosy and other techniques. The proposal mechanism involve a bi-radical from triplet excited state of isathine that react with C=N of the diisopfh and has a ring expansion. The successive pass would be thermal and with propanone elimination, as thermal rearrangement on phosphoric derivates described in the literature. In a second phase was studied, by Laser Flash Photolysis, the kinetic effect of the six aromatic derived of phosphoril-hidrazone (H, p-Cl, p-NO2, p-CN, p-NMe2 e p-CO2H) on the triplet excited state of four aromatic ketones: Xanthone, Tioxanthone, Benzophenone and Benzyl. The observed process to quencher, in all cases, was energy transference, because the rate constants are in the order of 1010M-1s-1. In this form was possible to estimate the energy of triplet excited state of these six phosphoril-hidrazone derivates.