Abstract
A potentiometric technique using a hydrogen electrode concentration cell with flowing solutions was employed to measure the ionization equilibria of cyclohexylamine and morpholine over the temperature range 50–295°C in dilute KCl media. Also, the isothermal pressure coefficients were determined to 250°C in the same media. Smoothing functions are presented which fit these and other selected data, and thermodynamic quantities for the ionization process were derived. Nearly linear variation of ΔH vsT ΔS was observed for this process as well as other similar reactions, and the significance is discussed. Differences in basicities of amines are found to decrease at elevated temperatures, and reversals in relative base strengths are seen.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
S. Bergström and G. Oloffson,J. Solution Chem. 4, 535 (1975).
H. B. Hetzer, R. G. Bates, and R. A. Robinson,J. Phys. Chem. 70, 2869 (1966).
H. K. Hall, Jr.,J. Am. Chem. Soc. 79, 5441 (1957).
F. E. Condon,J. Am. Chem. Soc. 87, 4481, 4485, 4491, 4494 (1965).
F. E. Condon, R. T. Reece, D. G. Shapiro, D. C. Thakker, and T. B. Goldstein,J. Chem. Soc. Perkin Trans. 2, 1112 (1974).
F. H. Sweeton, R. E. Mesmer, and C. F. Baes, Jr.,J. Solution Chem. 3, 191 (1974).
B. F. Hitch and R. E. Mesmer,J. Solution Chem. 5, 667 (1976).
Chia-tsun Liu and W. T. Lindsay, Jr.,J. Solution Chem. 1, 45 (1972).
S. W. Benson,J. Am. Chem. Soc. 80, 5151 (1958).
A. J. Read,J. Solution Chem. 4, 53 (1975).
H. S. Harned and R. Davis, Jr.,J. Am. Chem. Soc. 65, 2030 (1943).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Mesmer, R.E., Hitch, B.F. Base strength of amines at high temperatures. Ionization of cyclohexylamine and morpholine. J Solution Chem 6, 251–261 (1977). https://doi.org/10.1007/BF00645456
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF00645456