A photoswitchable diarylethene heterodimer for use as a multifunctional logic gate

A novel multifunctional photochromic molecule, BTF-BTH, was synthesized via covalently linking two photoswitchable fluorescent diarylethenes BTFO4 and BTHTO, and the structure was characterized using NMR and MS analysis. The photophysical properties of four photoisomeric states, BTFo-BTHo, BTFc-BTHc, BTFc-BTHo and BTFo-BTHc, were studied. Interconversions among these states were readily achieved using light irradiation and the addition of Cu2+. Interestingly, a fluorescence energy transfer phenomenon was observed for BTFc-BTHc. Based on these results, logic gates, including OR, keypad lock, INHIBIT, AND, and 1:2 demultiplexer, were designed and successfully demonstrated using BTF-BTH.