Study on cation recognition properties of 4-methene6,7-dimethoxycoumarin-monoaza-18-crown-6

With the title new luminescent ionophore MDC-MAC(O5) as host, the cation recognition properties with Li+, Na+, K+, Mg2+, Ba2+ and Pb2+ in acetonitrile were studied by fluorimetry method and the corresponding stable constants and the sensitive factors of the guest-host complexes were determined by the modified H-B equation. The recognition mechanism between MDC-MAC(O5) and metal ion was discussed based on the chemical construction of MDC-MAC(O5) and the fluorescence enhancement effect during they interaction each other. Because the carbonyl group of the coumarin participates in the complexation between the crown ether and the cation, and N electron of oxygen atom of CH3-group can promote the complexation by the way of the resonance, the stability of the complexes was increased obviously