Temperature dependence studies and microscopic protonation constants of L-alanine and beta-alanine in acetonitrile - water mixtures

Erensoy H., BİLĞİÇ ALKAYA D., AYAZ SEYHAN S.

OVIDIUS UNIVERSITY ANNALS OF CHEMISTRY, cilt.33, sa.2, ss.99-103, 2022 (ESCI) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 33 Sayı: 2
  • Basım Tarihi: 2022
  • Doi Numarası: 10.2478/auoc-2022-0014
  • Dergi Adı: OVIDIUS UNIVERSITY ANNALS OF CHEMISTRY
  • Derginin Tarandığı İndeksler: Emerging Sources Citation Index (ESCI)
  • Sayfa Sayıları: ss.99-103
  • Anahtar Kelimeler: L-alanine, beta-alanine, microscopic protonation constants, thermodynamics parameters, PK(A) VALUES, THERMODYNAMIC PARAMETERS, STABILITY-CONSTANTS, AQUEOUS-SOLUTIONS, ACIDS, SOLUBILITY, SOLVENT
  • Marmara Üniversitesi Adresli: Evet

Özet

L-alanine and beta-alanine are important biological molecules and have zwitterion structure. In this study, L-alanine and beta-alanine's microscopic protonation constants and thermodynamic parameters (enthalpy, entropy, and free energy changes) for the proton-ligand systems of L-alanine methyl ester, beta-alanine and beta-alanine methyl ester have been determined at 5; 20; 35 degrees C, in ACN-water (25% ACN and 50% ACN (v/v)) mixtures at constant ionic strength of 0.1000 mol NaClO4 by potentiometric method. The results shown that, L-alanine and beta-alanine's microscopic protonation constants generally tend to decrease with temperature rise and their protonation reactions in ACN-water mixtures generally favor enthalpy-driven.