Jl. Gundersen et Wg. Macintyre, DISSOCIATION-CONSTANTS OF CHLOROGUAIACOLS IN WATER - A COMPARISON OF MEASURED AND PREDICTED VALUES, Environmental toxicology and chemistry, 15(6), 1996, pp. 809-813
Chloroguaiacols are common components of bleached-kraft pulp mill effl
uent known to bioaccumulate in aquatic organisms and to sorb on partic
ulate material and sediments. Ionization properties of the chloroguaia
cols must be known in order to explain their sorptive behavior in aqua
tic systems. To obtain this information, thermodynamic acid dissociati
on constants (pK(a)) of guaiacol (o-methoxyphenol) and nine chloroguai
acols have been determined by spectrophotometric methods. These experi
mental pK(a) values have been compared with literature values, values
predicted by the Hammett equation, and predictions by quantum chemical
calculations using MOPAC 6.0 with AM1 and MNDO Hamiltonian operators.
Experimental and predicted acidities were strongly correlated, and th
e correlation equations obtained have been used to calculate pK(a) val
ues for those chloroguaiacols that were unavailable for experimental m
easurement.