Determination of acidity constants for some indole derivatives

ABSTRACT Master of Science Thesis DETERMINATION OF ACIDITY CONSTANTS FOR SOME INDOLE DERIVATIVES DENİZ HÜR Anadolu University Graduate School of Natural and Applied Science Chemistry Program Supervisor: Yrd.Doç.Dr. Alaattin Güven 2000 We present an experimental and theoretical studies for the estimation of pKa values of some 1-, 2- and 1,2-substituted indoles in aqueous solution by spectroscopic and semiempirical methods. When the pKa values of these compounds have been calculated both experimentally and theoretically the tautomeric equilibria and conformers were also considered, if available, to find out the most tautomers and conformers. The substituent effects on the protonation of 1-, 2- and 1,2-substituted indoles were investigated by using the calculated and experimental pKa values. The calculated pKa values were correlated with the experimental ones. Keywords: Indole, tautomeric equilibrium, conformation, acidity and basicity (pKa), semiempirical calculation