
TY  - JOUR
A1  - van, Gemert JT 
T1  - The ionization constants of phenolic groups in hydroxynaphthalenesulphonic acids
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1969
VL  - 22
IS  - 9
SP  - 1883
EP  - 1890
KW  - 
UR  - https://doi.org/10.1071/CH9691883 
N2  - Ionization constants of the hydroxyl group have been determined for a series of hydroxynaphthalenesulphonic acid salts. Thermodynamic pKa values have been determined for one mono- and one di-sulphonate. The effect of ionic strength is twice as great for the sulphonates as for naphthols. A large difference in acid strength between 1- hydroxynaphthalene-2-sulphonate and 2-hydroxynaphthalene-1-sulphonate has been explained in terms of interaction with the peri-hydrogen atom in the latter. Dewar and Grisdale's expression for substituent effects has been applied to the hydroxynaphthalenesulphonates with nonadjacent substituents. It is concluded that the limitations of the FM treatment are most severe with strongly dipolar substituents and with reaction sites such as -OH and -NH, capable of inducing secondary resonance effects. 
ER  -

