Construction and Chemometric Analysis of Acidity Function in Perchloric Acid

Autor:	Jiří Kulhánek, Taťjana Nevěčná, Oldřich Pytela, Eva Jirásková
Rok vydání:	1999
Předmět:	Aqueous solution medicine.diagnostic_test Chemistry Analytical chemistry Protonation General Chemistry Chemometrics chemistry.chemical_compound Spectrophotometry Principal component analysis medicine A value Organic chemistry Perchloric acid Acidity function
Zdroj:	Collection of Czechoslovak Chemical Communications. 64:1253-1261
ISSN:	1212-6950 0010-0765
Popis:	Four 2,6-disubstituted anilines with CH3, Cl, and NO2 substituents have been synthesized and, together with four commercial substances of the same type, subjected to spectrophotometry to find the concentration ratios of the protonated and non-protonated forms in aqueous perchloric acid of 0.02-10.55 mol dm-3 concentration. By a procedure devised earlier, the acidity function has been constructed and the pKa values calculated. The Principal Component Analysis was applied to the acidity function obtained and on other eight acidity functions of perchloric acid were taken from literature. It was found that the first principal component explained 99.78% of variability, which indicated high degree of similarity of the said functions irrespective of the indicator type and solvent used. The regression dependences acidity function values on the first principle component are very close, the regression coefficient expressing the measure of sensitivity of the indicator to the acidifying medium. The pKa values obtained agree well with the literature data.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::61c3c41a29b45ad4f8296698e237bb85 https://doi.org/10.1135/cccc19991253 Zobrazit plný text záznamu