Tropolone-triethylamine equilibria in various solvents

Abstract

Infrared and nuclear magnetic resonance spectroscopic methods were used to study the tropolonetriethylamine equilibria. In aprotic solvents tropolone transfers its proton to triethylamine to form an ion pair which is in equilibrium with the intramolecularly hydrogen-bonded tropolone. The extent of ion pair formation increases with the dielectric constant of the aprotic solvent. Unlike the case of the p- nitrophenol-triethylamine system, there is no formation of a hydrogen bonded complex between tropolone and triethylamine. In the case of the tropolone-dibutylamine system in aprotic solvents, only ion pair formation is observed.