Photophysical and anion sensing properties of a triphenylamine-dioxaborinine trimeric compound.

Herein, we report the synthesis and photophysical characterization of the novel tris(4-(2,2-difluoro-6-methyl-2 H -1λ 3 ,3,2λ 4 -dioxaborinin-4-yl)phenyl)amine trimeric probe (A2) via the reaction between triphenylamine (1), acetic anhydride, and BF 3 ·OEt 2 implying the twelve new bond formation in a one-pot manner. This highly fluorescent compound in solution ( φ up to 0.91 at 572 nm) and solid state ( φ = 0.24 at 571 nm) showed a better solvatofluorochromism than its analog monomeric A1 due to symmetry-broken charge transfer, which is consistent with high solvent dipolarity (SdP) response in Catalán's multiparametric regression. Notably, A2 had a high sensibility and selectivity for CN - or F - in solution (LODCN - /F - = 0.18/0.70 μM), and CN - can be discriminated from F - by the reaction of A2 with 3.0 equiv. of CN - . In addition, A2 was impregnated on filter paper to prepare test strips that were applied to naked-eye qualitative sensing of CN - or F - . Finally, the octupolar system in A2 allows for better action of two-photon excitation cross-section values when compared with that of the dipolar structure in A1. These findings provide further information for the design of new efficient two-photon absorption dyes.