Anion sensing and F(-)-induced reversible photoreaction of D-π-A type dye containing imidazole moiety as donor.

A new donor-π-acceptor (D-π-A) type dye was synthesized by the condensation reaction between 2-cyanomethylene-3-cyano-4,5,5-trimethyl-2,5-dihydrofuran and 4-imidazolecarboxaldehyde. The chemical structure of the dye was characterized by (1)H NMR, EA and MS. A novel chromogenic dye based on imidazole as donor unit and furan as acceptor unit displayed marked UV-visible absorption changes in the presence of fluoride ion. The levels of energy potential and the electron density distributions of this dye were also simulated and discussed using computational model calculation. The reversible photoreaction of the dye-F(-) complex was studied by time-dependent UV-visible absorption spectra.