SUBSTITUENT AND SOLVENT EFFECTS ON THE UV ABSORPTION SPECTRA OF N-(SUBSTITUTED PHENYL)-CYANO-ACETAMIDES

Abstract

Phenylacetamide derivatives are a group of organic compounds having a wide range of activity and turout to be particularly important for pharmaceutical, agriculture and toxicological application. Several phenyl- acetamides displayed potent anticonvulsant, antileishmanial, antimicrobial and antifungal activity. Because of widely biological activities of phenylacetamide derivatives, synthesized N- (substituted phenyl) cyano-acetamides become interesting for different purpose. The aim of this paper is to investigate substituent and solvent effects on the UV absorption spectra of N-(substituted phenyl)-cyano-acetamides. Absorption spectra of ten N-(substituted phenyl)-cyano-acetamide derivatives have been recorded in 4 protic and 4 aprotic solvents in the range 200-320 nm. The substituents at the phenyl nucleus are as follows: H, CH3, I, Br, NO2, OH, COOH, SO3H, COCH3 and C2H5. The effects of substituents on the absorption spectra of these new derivatives of acetamide are interpreted by correlation of absorption maximum with Hammett substituent constant, s. The solute-solvent interactions were clarified on the basis of linear solvation energy relationships (LSER) concept proposed by Kamlet and Taft. The multiple linear regression equation electronic spectra data correlated with solvatochromic parameter p*, a and ß. It was found that the absorption frequencies for investigated derivatives in used solvents show satisfactory correlation with solvatochromic parameters. The quantitative relationship between the molecular structure and the chemical reactivity is discussed, as well as the effect of geometry on the reactivity of the examined molecules.