Protonation Equilibria of Biologically Active Ligands in Mixed Aqueous Organic Solvents

Table 2

The autoprotolysis constants () obtained for various water-organic solvent mixtures measured in an ionic medium of 0.1 mol·dm⁻³ NaClO₄ at 25°C^a.

Organic component	Organic component %
	0	10	20	30	40	50	60	70	80
Methanol	13.69	13.75	13.78	13.70	13.73	13.71	13.72	13.77	13.94
Ethanol	13.69	13.82	13.99	14.16	14.24	14.28	14.39	14.59	14.77
1-Propanol	13.69	13.78	13.98	14.04	14.15	14.31	14.46	14.61	14.82
2-Propanol	13.69	13.76	13.95	14.05	14.26	14.34	14.56	14.79	—
Dioxane	13.69	13.91	14.22	14.51	14.86	15.24	15.62	—	—
Acetonitrile	13.69	13.96	14.19	14.44	14.74	15.04	—	—	—

^aData taken from reference [37].
The % is expressed as (volume/Volume).