Abstract
Acid dissociation and anionic homoconjugation equilibria of 1,4-dihydroxy-, 1,5-dihydroxy-, and 1,8-dihydroxyanthraquinone were studied by means of potentiometry and UV-spectroscopy in the following polar non-aqueous solvents of varying dielectric and acid–base properties: acetonitrile, dimethyl sulfoxide, and methanol. The measurements were carried out under anaerobic conditions, in order to prevent the oxidation of phenolic parts. The determined p K a ’s range from about 12–14 in dimethyl sulfoxide and methanol to about 22–24 in acetonitrile; the most acidic compound being the 1,8-derivative and the least acidic the 1,5-derivative. The logarithms of anionic homoconjugation constants are of the order of 2–3 in all solvent studied.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
