SPECTROSCOPIC STUDIES ON INTRAMOLECULAR AND INTERMOLECULAR HYDROGEN-BONDING OF SOME O-HYDROXYLBENZENESULFONANILIDES IN SOLUTIONS

The effect of solvent on the electronic spectra of some fasciolicidal o-hydroxylbenzenesulfonanilides is examined and discussed. It is revealed that in solution these compounds exist in both intramolecular hydrogen bond form and intermolecular hydrogen bond form occurring between solute and solvent molecule. In solutions containing large amount of apolar aprotic solvents such as dioxane, compounds studied are mainly intramolecular hydrogen bond form and exhibit a weak transition band which is presumably attributed to the n-pi* transition of n-electrons of oxygen atom in the intramolecular hydrogen bonded six-membered ring of the compounds.