Novel receptors with quinoline and amide moieties for the biologically important ions

New chromogenic anion receptors 2 and 4 utilizing quinoline and nitrophenyl groups as signaling groups were synthesized. In these receptors, amide and amine groups made strong multiple hydrogen interactions with anions. The receptors 2 and 4 bind anions with a selectivity of F − > CN − > CH 3 CO 2 - and proved to be an efficient naked-eye detector for the fluoride and cyanide ion.