Jump to main content
Jump to site search

Issue 0, 1970
Previous Article Next Article

Proton ionisation constants and kinetics of base hydrolysis of some α-amino-acid esters in aqueous solution. Part II

Abstract

The thermodynamic proton ionisation constants, pKTa,A for the amino-groups of the acids, A, α-alanine, α-amino-n-butyric acid, norvaline, norleucine, valine, isoleucine, β-alanine, γ-amino-n-butyric acid, and serine have been determined at 25 °C and I= 0·1 M. The corresponding pKTa,E values for the ionisation of the methyl esters, E, have also been obtained. The temperature-dependence of pKTa,A and pKTa,E has been studied at the additional temperatures of 37 and 50 °C for α-alanine, α-amino-n-butyric acid, β-alanine, γ-amino-n-butyric acid, and serine. Values of ΔH° and ΔS°298 have been determined for the ammonium ionisation in each case, and the results obtained for the acids and their esters compared and discussed.

The base hydrolysis of the protonated (EH+) and unprotonated (E) forms of the methyl esters of α-alanine, α-amino-n-butyric acid, norvaline, norleucine, valine, and β-alanine has been studied at 25 °C and I= 0·1M. Values of ΔH298 and ΔS298 have been obtained for the E and EH+ forms of the methyl esters of α-alanine, α-amino-n-butyric acid, β-alanine, and for the unprotonated form of serine.

Back to tab navigation

Article type: Paper
DOI: 10.1039/J29700001577
J. Chem. Soc. B, 1970, 1577-1582

  •   Request permissions

    Proton ionisation constants and kinetics of base hydrolysis of some α-amino-acid esters in aqueous solution. Part II

    R. W. Hay and P. J. Morris, J. Chem. Soc. B, 1970, 1577
    DOI: 10.1039/J29700001577

Search articles by author

Spotlight

Advertisements