Potentiometric studies on the protonation constants and solvation of some alpha-amino acid methyl- and ethyl esters in ethanol-water mixtures


Dogan A., Koseoglu F., Kilic E.

INDIAN JOURNAL OF CHEMISTRY SECTION A-INORGANIC BIO-INORGANIC PHYSICAL THEORETICAL & ANALYTICAL CHEMISTRY, cilt.41, ss.960-962, 2002 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 41 Konu: 5
  • Basım Tarihi: 2002
  • Dergi Adı: INDIAN JOURNAL OF CHEMISTRY SECTION A-INORGANIC BIO-INORGANIC PHYSICAL THEORETICAL & ANALYTICAL CHEMISTRY
  • Sayfa Sayıları: ss.960-962

Özet

The stoichiometric protonation constants of 15 esters (methyl- and ethyl esters of glycine, L-alanine, L-valine, L-leucine, L-phenylalanine, L-serine, L-methionine and methyl ester Of L-isoleucine) in 20-80% (v/v) ethanol-water mixtures have been determined. The effect of solvent on cc-amino acid methyl- and ethyl esters have also been determined at ionic strength of 0.1 M NaCl and at 25degreesC under nitrogen atmosphere. A potentiometric method is used and the calculation of the constants has been carried out using PKAS computer programme. The logarithm of the protonation constants of alpha-amino acid esters is found to decrease linearly with increase in ethanol contents, The variation of these constants is discussed on the basis of specific solute-solvent interactions.