UV absorption spectra and reaction pathways for sulfonyl-dihidropyridine and fused derivatives through (TD)DFT calculations

MARÍA VICTORIA COOKE; GUADALUPE FIRPO; WALTER JOSE PELÁEZ; GUSTAVO ALEJANDRO ARGÜELLO

Bogotá

Exposici�n; Programme Régional France-Amérique Latine-Caraïbe; 2015

A detailed analysis of the MOs involved in electronic transitions in UV spectra as well as a conformational study of some 1-benzenesulfonyl- and 1-trifluoromethylsulfonyl derivatives have been carried out using the TD-DFT (B3LYP/6-31+G(d,p)) method. Based on experimental solvent effects and theoretical investigations the long-wavelength bands have been assigned to * transitions caused by HOMO?LUMO intramolecular charge transfer of the systems. Nevertheless, for one of the 1-benzenesulfonyl- (p-NO2) derivative the HOMO?LUMO transition was found to be forbidden. In this case the long-wavelength band has been associated to an n* transition. Good correlation of theoretical and experimental data for the energy transitions and the molar extinction coefficients of the compounds studied has been obtained and is presented for the first time.