Binaphthyl-derived salicylidene Schiff base for dual-channel sensing of Cu, Zn cations and integrated molecular logic gates

The 2,2′-bis(3,5-dichloro-2-hydroxybenzylideneamino)-1,1′-binaphthyl salen-type Schiff base (BCHB) has been synthesized and characterized. Exhibiting absorption and fluorescence changes in the presence of Cu2+ and Zn2+ in tetrahydrofuran (THF) solution, BCHB could be used as a colorimetric ‘naked eye’ and fluorescent chemosensor for the detection of Cu2+ and Zn2+ bi-functionally. Furthermore, this organic ligand can selectively recognize Cu2+ and Zn2+ in the presence of other metal ions (such as Na+, Ag+, Mn2+, Co2+, Ni2+, Fe3+, Cd2+, Hg2+, Pb2+, La3+, and Nd3+), respectively. On the other hand, BCHB presents a tunable system integrated with one OR logic gate as well as one INHIBIT logic gate with Zn2+ and Cu2+ as chemical inputs by monitoring fluorescence and absorbance as output signals. Also, one IMPLICATION gate operating in fluorescence mode with Cu2+ and EDTA as chemical inputs, based on their different binding capabilities, is present in this system.