Azocalix[4]arene with three distal ethyl ester residues as a highly selective chromogenic sensor for Ca2+ ions

[摘要] Three azocalix[4]arenes with distal ethyl ester residues, 5-phenylazo-25,26,27-tris[(ethoxycarbonyl)methoxy]-28-hydroxycalix[4]arene ( 2 ), 5-(o-methylphenyl)azo-25,26,27-tris[(ethoxycarbonyl)methoxy]-28-hydroxycalix[4]arene ( 3 ), 5-(p-Methylphenyl)azo-25,26,27-tris[(ethoxycarbonyl)methoxy]-28-hydroxycalix[4]arene ( 4 ), were synthesized and their binding properties with metal ions were investigated by ultraviolet (UV)/visible spectroscopy. The chromogenic behavior of these compounds upon metal ion complexation indicates a specific selectivity toward Ca 2+ ion in the presence of other cations tested. The stoichiometry of 3 to Ca 2+ ion in the complex is 1:1 and the stability constant of the complex is 1.28×10 4 m −1 .

[学科分类] 内科医学

[关键词] azocalix[4]arene;calcium ion;chromogenic sensor;ion recognition