ISSN:
0894-3230
Keywords:
Chemistry
;
Theoretical, Physical and Computational Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
A study of the acid-base behaviour of the three isomeric pyridinecarboxylic acids (picolinic, nicotinic and isonicotinic acid) was carried out using spectrophotometric and potentiometric measurements. The cationic form of picolinic acid converts partially into the corresponding zwitterion (pK1) within a borderline acidity range where neither the pH scale nor the acidity functions work satisfactorily. Protonation of the carboxyl groups (pK33) occurred at the highest acidity levels employed. The medium effects observed on the spectral curves were corrected by factor analysis. The potentiometric measurements gave values for pK1 and pK2 only, which were in good agreement with those determined spectrophotometrically.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
