Thermodynamic parameters for the basic ionization of some cyclic amines in water

Abstract

SHEILA TERESA LOBO, TANIKELLA S. S. R. MURTY, and Ross ELMORE ROBERTSON. Can. J. Chem. 54, 3607 (1976).The thermodynamic parameters defining the basic dissociation in water of diethylamine, cyclohexylamine, piperidine, and quinuclidine have been determined by a dilution method based on conductance measurements. 54, 3607 (1976).Les paramktres thermodynan~iques dkfinissant la dissociation basique, dans l'eau. de la diethylamine, de la cyclohexylamine, de la pipCridine et de la quinuclidine ont Ct C determinis par une mkthode de dilution basCe sur des mesures de conductivitCs. A 25 ^C, les valeurs de ASaO et de ACPa0 pour l'ionisation acide des ions ammonium correspondants sont ASaO -8.08, -1.24, -8.51, -13.65 cal deg-I molkl et ACPa0 13.9, -2.7, 18.0, 4.2 cal deg-1 mol-1. On discute de la relation entre ces valeurs dCriv6es et les changements dans la solvation: on note les valeurs apparemment anormales du ACDaO de la cyclohexylan~ine et de la quinuclidine mais on ne peut les rationaliser.[Traduit par le journal] Introduction In this paper we report the thermodynamic quantities defining the ionization of certain cyclic amines in water and note the relationship between these quantities and structure.The search for structure-reactivity relationships for the ionization of amines in water has a long history (1-8). The simple approach, based on a comparison of pKa values, led to the well-

Thermodynamics of basic ionization of some aminoethers in water

“…Although Kb values were determined on the molar scale, they were converted to the molal scale (17 (18). The method of evaluation of K, from the ShedlovskyKay equation (19) has been given elsewhere (15)(16)(17).…”

“…Although Kb values were determined on the molar scale, they were converted to the molal scale (17 (18). The method of evaluation of K, from the ShedlovskyKay equation (19) has been given elsewhere (15)(16)(17). In Table 2 are reported the values of the 'Corresponding data for the ionization of bis-2-metlioxyetl~ylamine and 3-niethoxypropylamine are available, at a nominal charge, from the Depository of Unpublished Data, CISTI.…”