pH-controlled hydrogen-bonding (Short Communication)
- 1 December 1974
- journal article
- Published by Portland Press Ltd. in Biochemical Journal
- Vol. 143 (3) , 775-777
- https://doi.org/10.1042/bj1430775
Abstract
The pH-dependence of the degree of hydrogen-bonding between a base and its conjugate acid is considered. When only a small proportion of the total base is complexed, the amount complexed is proportional to (1+coshp)−1 where p=2.303 (pKa–pH), pKa being the dissociation constant of the conjugate acid. This represents sharp pH-dependence. As the proportion complexed increases, the curve broadens, eventually becoming flat-topped, with more than half the base complexed over the range of pH values pKa±logKC, approximately. (K is the complex association constant and C is the formal base concentration, including all forms.) There are similarities to the extent of mono-protonation of a dibasic acid.Keywords
This publication has 2 references indexed in Scilit:
- Curves of ligand binding. The use of hyperbolic functions for expressing titration curvesBiochemical Journal, 1974
- Shapes of curves of pH-dependence of reactionsBiochemical Journal, 1973