A new N-substituted heteroacene can detect CN^- and F^- anions via anion-π interaction

A novel heteroacene with an aroyleneimidazophenazine moiety (1) has been successfully synthesized and characterized. Compound 1 can selectively detect CN^- and F^- over another ten anions (Cl^-, Br^-, I^-, Ac^-, H₂PO₄ ^-, NO₃^-, SO₄^2-, ClO ₄^- and BF₄^-, PF₆ ^-) in mixed solvents with multiple responses including fluorescent "turn-off", colorimetric and near-infrared absorption signaling. The interactions between 1 and CN^-/F^- have been investigated through UV-vis and fluorescence experiments, and the results suggest that the anion-π interactions between 1 and CN^-/F^- might be reversible processes upon the addition of Cu²⁺ and Fe³⁺ cations.