Multifunctional substances ? Determination of pKa-values by various methods

Autor:	Y. Hamachi, T. Kuriki, N. Sistovaris
Rok vydání:	1991
Předmět:	Aqueous solution Strong acids Chemistry Inorganic chemistry Piretanide Biochemistry Acid dissociation constant Analytical Chemistry Ion chemistry.chemical_compound Organic chemistry Titration Carboxylate Solubility
Zdroj:	Fresenius' Journal of Analytical Chemistry. 340:345-349
ISSN:	1618-2650 0937-0633
DOI:	10.1007/bf00321579
Popis:	The determination of multiple pKa-values in chemical substances is described using alternatively 1. titrations in oversaturated aqueous solution; 2. titrations in mixed solvents; 3. UV-spectra; 4. octanol-water partition ratios; 5. solubility data. Piretanide with three acid/base functional groups was used as model substance. Values obtained from these methods agreed well: 1. The imino-function is protonized by strong acids, pK1=1.3; 2. the carboxylate anion is formed in the neutral range, pK2=3.85; 3. the sulphonamide dissociates under alkaline conditions, pK3=10.0. Results were compared to those of furosemide, which were obtained by the same methods or from previously published data.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::3d1e583b6b83c671ed7c16e4f3e6c3fb https://doi.org/10.1007/bf00321579 Zobrazit plný text záznamu Full text from SpringerLink