Le molecular sensor. Supported by density functional theory (DFT) and time-dependent density functional theory (TD-DFT) studies, imidazole rings containing fluorophores have been shown to act selectively as fluoride sensors via hydrogen bond formation and, in some instances, subsequent deprotonation [45,53,54]. In an effort to combine the desirable properties of tetraphenylethylene and imidazole moieties for the development of extremely selective sensors, the present operate describes the synthesis, characterization and optoelectronic properties of a TPE-linked bis(thienyl) imidazole derivative and its application as a fluoride sensor.Chemosensors 2021, 9,three ofhemosensors 2021, 9, x FOR PEER REVIEW3 ofFigure 1. Examples of (a) tri-benzimidazoyl-, (b) -corboline-imidazopyridine-, (c) pyrenoimidazFigure 1. Examples of (a) tri-benzimidazoyl-, (b) -carboline-imidazopyridine-, (c) pyrenoimidazolyl-, olyl-, and (d) napthoimidazole dione- based molecular sensors usedused for fluoride detection. and (d) napthoimidazole Nourseothricin Antibiotic dione-based molecular sensors for fluoride detection.2. Components investigation, Based on Ye’sand Approaches [45,53,54] the mechanism behind the anion sensing ability of imidazole-based sensors is through the formation of N-H—X-(St. Louis, bondsUSA) and used All chemical substances were obtained from Sigma Aldrich hydrogen MO, or by deprotonation (mono-proton transfer), resulting in changes to their optical properties. freshly as received. Tetrahydrofuran was used for the sensing experiments, which was Fluoride ions have a distilled prior to use. 1 H and 13 Cgroup, spectra had been recordedbonding Avance dried and powerful affinity towards the N-H NMR promoting hydrogen on Bruker with all the imidazole molecular sensor. Supported by density spectrometer (Karlsruhe,and 400, Varian Inova 500 or Bruker Avance 300 MHz functional theory (DFT) Germany) at space density functional theory (TD-DFT) research, imidazole referenced to TMS time-dependenttemperature. Chemical shifts () are reported in ppm andrings containing (1 H) or residual been shown to act selectively as constants (J) are reported in Hz. Mass fluorophores have solvent signals (13 C) and couplingfluoride sensors via hydrogen bond spectra formationwere in some instances, subsequent deprotonation [45,53,54]. In Karlsruhe, Germany) or Water and, obtained making use of a Bruker Autoflex Speed (MALDI-TOF, an work to combine Quattro Micro of tetraphenylethylene and imidazole moieties for the develop- recorded the desirable properties (ESI) spectrometer (Karlsruhe, Germany). UV-vis. spectra have been on an Agilent sensors, the present work describes 20000 nm as THF solutions. FT-IR ment of very selective Cary 60 spectrometer within the range of the synthesis, characterizaspectra had been properties a a TPE-linked bis(thienyl) imidazole derivative and tion and optoelectronicrecorded on ofPerkin Elmer Spectrum (Akron, OH, USA) one hundred spectrometer as KBr as a fluoride sensor. its application discs. two.1. Computational two. Supplies and Techniques Techniques Computational calculations were performed utilizing the Gaussian used as All chemicals were obtained from Sigma Aldrich (St. Louis, MO, USA) and 09 computer software suite. The initial geometries of the CGS 21680 Protocol DTITPE probe were constructed making use of Gauss View 05 and received. Tetrahydrofuran was utilized for the sensing experiments, which was freshly dried optimized use. 1 the DFT/Becke, 3-parameter, lee ang arr(B3LYP)/6-31+G(d,p) level and distilled prior to using H and 13C NMR spectra had been recorded on Bruker Avance 400,.