Conjugation and proton exchange equilibria: an electrometric method for determination of heteroconjugation constants in solvents of weak proton donating and weak proton accepting properties Original Research Article

The fundamentals of the method for determining the heteroconjugation constantsKAHA−1=[AHA−1][HA]·[A−1]in solvents of weak proton donating and weak proton accepting properties from e.m.f. measurements are given. The method has been tested for 2,4,6-trichlorophenol-substituted phenolate systems in acetonitrile. The heteroconjugation constants determined appeared to be overestimated in relation to the values expected from the equation given previously. The observed deviations were found to be caused essentially by formation of heteroconjugates between proton donors and proton acceptors with the solvent molecules (not taken into account in calculations).