PROTONATION CONSTANTS OF SOME PYRIDINE-DERIVATIVES IN ETHANOL-WATER MIXTURES


KILIC E., KOSEOGLU F., BASGUT O.

ANALYTICA CHIMICA ACTA, cilt.294, sa.2, ss.215-220, 1994 (SCI İndekslerine Giren Dergi) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 294 Konu: 2
  • Basım Tarihi: 1994
  • Doi Numarası: 10.1016/0003-2670(94)80197-5
  • Dergi Adı: ANALYTICA CHIMICA ACTA
  • Sayfa Sayıları: ss.215-220

Özet

Protonation constants of a number of mono- and disubstituted pyridines were determined potentiometrically in 0, 10, 20, 30, 40, 50, 60, 70, 80% (v/v) ethanol-water mixtures at 25 degrees C with an ionic strength of 0.1 M. Data were calculated by a computer programme. The logarithm of the protonation constants of pyridines linearly decreased with increase of ethanol contents but the values determined in water and 80% ethanol did not follow this linear trend. Furthermore, the effects of the substituents on the basicity of pyridine, the additivities of these effects and the applicability of the Hammett equation to the behaviour of substituents are discussed.