Croatica Chemica Acta, Vol. 72 No. 4, 1999.
Izvorni znanstveni članak
UV Study of the Protonation of Indole-2-carboxylic Acid, 3-Methylindole, 3-Acetylindole and D-Tryptophan in Perchloric Acid Solutions
Blagoja S. Andonovski
; Institute of Chemistry, Faculty of Science, The Sv. Kiril i Metodij University, P. O. Box 162, 91001 Skopje, Republic of Macedonia
Sažetak
Protonation of indole-2-carboxylic acid, 3-methylindole, 3-acetylindole and D-tryptophan in perchloric acid media was studied by UV spectroscopy methods in the 400–190 nm region. Absorbance values were measured at four selected wavelengths and the molar absorptivity was calculated. From these values, the pKa's were determined using Hammett's equation. Also, the dissociation constants and solvent parameter m* were obtained by the Excess Acidity Method. The position of additional protons in protonated compounds was discussed.
Ključne riječi
UV spectra; protonation; indole-2-carboxylic acid; 3-methylindole; skatole; 3-acetylindole; D-tryptophan; dissociation constants; Hammett; acidity functions; excess acidity
Hrčak ID:
132271
URI
Datum izdavanja:
1.12.1999.
Posjeta: 1.462 *