Dergiler / Turkish Journal of Chemistry / 2002 / Cilt: 26 - Sayı: 6

The Protonation Constants of Some Aliphatic Alkylamines in ethanol-water Mixtures

Sayfa
843–851
DOI
—

Özet

Protonation constants of methyl-, ethyl-, propyl- and butylamines Were determined potentiometrically using an electrode system calibrated in concentration units of hydrogen ion in ethanol-water mixtures (10% -80% ethanol, v/v) at an ionic strength of 0.1 and at 25°C. The trend in the values of protonation constants of these aliphatic amines was explained in terms of the number of alkyl groups and solvent composition. The basicity orders were found to be NH3 < R3N < RNH2 < R2NH (R:-CH3, -C2H5, -n-C3H7 and --n-C4H9) in all the solvent mixtures studied.

Abstract

Protonation constants of methyl-, ethyl-, propyl- and butylamines Were determined potentiometrically using an electrode system calibrated in concentration units of hydrogen ion in ethanol-water mixtures (10% -80% ethanol, v/v) at an ionic strength of 0.1 and at 25°C. The trend in the values of protonation constants of these aliphatic amines was explained in terms of the number of alkyl groups and solvent composition. The basicity orders were found to be NH3 < R3N < RNH2 < R2NH (R:-CH3, -C2H5, -n-C3H7 and --n-C4H9) in all the solvent mixtures studied.

Anahtar kelimeler: Aliphatic amines, potentiometry, protonation constant, ethanol-water mixtures.