Bithiophene triarylborane dyad: An efficient material for the selective detection of CN− and F− ions

A new fluorescent chemosensor based on bithiophene coupled dimesitylborane (BMB‐1) was synthesized and characterized. BMB‐1 was used for colorimetric and turn‐on fluorescent sensing of cyanide (CN−) and fluoride (F−) ions, in the presence of other competitive anions in an aqueous (CH3CN–H2O) medium. BMB‐1 showed a hypsochromic shift (blue shift) with addition of CN− and F− ions in absorption studies. The lower detection level of CN− and F− ions is 1.37 × 10−9 and 1.75 × 10−9 M, respectively. The BMB‐1 binding mechanism is based on the nucleophilic addition of CN− and F− ions in the internal charge transfer transition of bithio moiety to the boranylmesitylene unit, and the color changes were observed under UV light. This result is further confirmed by Fourier transform infrared spectroscopy, mass spectrometry and density functional theory calculations. Also, the BMB‐1 probe is found to be a good adsorbent for the removal of F− ions in real water samples using the adsorption technique. Bithiophene TriArylborane dyad: an efficient material for the selective detection of CN‐ and F‐ Ions. The dyad was successfully synthesized and structurally optimized by XRD. The selective sensing of CN‐ and F‐ Ions was confirmed by optical, FT‐IR, and 1H NMR studies and theoretical density functional calculations. The real sample detection activities are also investigated.