Effect of methoxy substituents on fluorescent Zn2+/Cd2+ selectivity of bisquinoline derivatives with a N,N′-dimethylalkanediamine skeleton

Introduction of three methoxy groups at 5-, 6- and 7-positions of quinoline rings of BQDMEN ( N , N ′-bis(2-quinolylmethyl)- N , N ′-dimethylethylenediamine) affords Cd 2+ -selective fluorescence enhancement.