Effect of substituents on cation-receptor properties of crown-containing 1-hydroxyanthraquinone imines

Resumo

Complex formation properties of new crown-containing 1-hydroxyanthraquinone imines with donor and acceptor substituents in the anthraquinone nucleus were studied. The compounds were prepared by photochemical reactions of 4-aminobenzo-15-crown-5-ether with photoactive derivatives of 1-phenoxyanthraquinone. It has been established that the introduction of acceptor substituents causes a shift of the prototropic tautomeric imine-enamine equilibrium towards the formation of the NH-form. As a result, significant cation-induced spectral changes are observed during complex formation.