Tetrabutyl ammonium salts

All the solvents and reagents used for synthesis were of analytical grade that were purchased from Oakwood Chemicals and Sigma Aldrich. The reaction was carried out under standard conditions using oven-dried round bottom flask. Progress of the reaction was monitored by TLC using silica-gel based thin layers in a solvent ratio 1 : 3 (ethyl acetate: petroleum ether). All the ions such as fluoride (F⁻), bromide (Br⁻), acetate (AcO⁻), chloride (Cl⁻), cyanide (CN⁻), perchlorate, and bisulfate in the form of tetra butyl ammonium salts were purchased from Sigma Aldrich. The structure of synthesized chemosensors IF-1 and 1F-2 were confirmed using ¹H-NMR, HRMS and UV-visible characterization techniques. Solvents used for analysis were of spectroscopic grade. ¹H-NMR and ¹³C NMR spectra were obtained at frequencies 300 MHz and 100 MHz respectively in DMSO-d₆ solvent where TMS was used as internal standard. The absorption and transmission studies of light (UV-vis spectroscopy) were recorded using Shimadzu UV-1800 spectrophotometer.