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

Abstract

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.

(Dimesityl)boron Benzodithiophenes: Synthesis, Electrochemical, Photophysical and Theoretical Characterization

“…leads to almost complete quenching (≈90 %) of the initial emission peaks (340 nm and 470 nm, respectively) for both BDT 1 derivatives. Absorption and fluorescence titration experiments revealed that both mono‐ and bis‐borylated benzodithiophenes have a great response to the addition of fluorides, according to what had been reported for similar dimesitylboryl‐functionalized scaffolds [11b,19] . These results indicate that compound 1 and 2 are promising scaffolds for applications as building blocks for fluoride‐detecting turn‐off sensor materials.…”

Organochalcogen substituted dimesityl borane-imidazoles as fluorogenic fluoride and cyanide sensors in aqueous media

“…2(a)). 7 Upon changing the heteroatom from –PPh 2 ( 6 ) (332 nm, DMF) to S( 7 ) to Se ( 8 ) (332 nm, CH 3 CN) no considerable change was observed in their absorbance maxima (Fig. 2(a)).…”

“…The bond distances of B–F in 8 -[F], 9 -[F], and 11 -[F] are 1.482(2) Å, 1.470(8) Å, and 1.462(4) Å, respectively, and the B–C (B–CN) bond distance in 7 -[CN] and 8 -[CN] are 1.634(3) Å and 1.623(7) Å respectively, which are typical of that obtained in other fluoroborates and cyanoborates such as [Ph 3 BCN] − (1.65 Å). 7,14…”

“…5 b ,6 Furthermore, to enhance the Lewis acidity and binding affinity of boron in organic–aqueous media for anion detection through fluorogenic and colorogenic response, various groups have made modifications to the triaryl borane unit like (a) substituting aryl groups with electron-withdrawing substituents, (b) replacing the aryl moiety with heterocyclic linkers (pyridine, picolines, thiophenes or azoles), (c) adding a cationic moiety in the vicinity of boranes, and (d) introducing an additional organoborane unit. 5 b ,7 Among them, the cationic moiety (ammonium, sulphonium, phosphonium, etc .) in the proximity of triarylboranes over the benzene or naphthalene (homocyclic) group has been extensively studied.…”

A novel turn‐on fluorometric “reporter‐spacer‐receptor” chemosensor based on calix[4]arene scaffold for detection of cyanate anion

“…At this standpoint, highly popular approaches such as multiple hydrogen bonding, anion-π, and supramolecular electrostatic interactions have been frequently used for the instantaneous fluorometric recognition [34][35][36]. In this sense, such macrocyclic compounds based on various classic skeletons such as crown ethers, cyclodextrins, cucurbiturils, and pillararenes have been often employed as receptors for anion sensing due to leading to a wider detection range, lower detection limit, and excellent ability to prevent interferences against coexisting ions [37][38][39][40].…”