THEORETICAL AND EXPERIMENTAL STUDY OF THE BENZALACETOPHENONE PHOTOCHEMICAL ISOMERIZATION

MONTAÑA M.P.; NIETO VAZQUEZ R.; PAPPANO N. B.; DEBATTISTA N. B.

Santa Caterina, Brasil

Congreso; 14th INTERNATIONAL and 4th LATINAMERICAN CONFERENCE ON PHYSICAL ORGANIC CHEMISTRY; 1998

IUPAC - Universidad de Santa Caterina

It was observed that the various benzalacetophenone synthesis give trans-s-cis isomers. This was verified by thin layer chromatography, high performance liquid chromatography (HPLC) and magnetic nuclear resonance with paramagnetic shift reactive in carbon tetrachloride solution. In the present work the transformation of these compounds was investigated, when they are exposured at the UV-radiation (l max 366 nm) in methanol solution. The kinetic and the equilibrium studies of photochemical isomerization trans-s-cis to cis-s-cis, were carried by HPLC. Measurements of the susbtrate samples, at different times of radiation were made. The results obtained were analysed using a development polynomial of time. The specific rates and equilibrium constants of the configurational transformation were determined. On the other hand, reactant, product and transition state geometries, involve orbitals and thermodynamic functions were obtained by theoretical calculations (Mopac 93).