Synthesis, application and AIE properties of novel fluorescent tetraoxocalix[2]arene[2]triazine: The detection of a hazardous anion, cyanate

A highly effective, new heterocalixarene fluorescent receptor comprised of 2-(2-aminophenyl)benzothiazole and tetraoxacalix[2]arene[2]triazine was designed and synthesized by one-step reaction. The sensor candidate exhibiting aggregation induced emission (ALE) was tested for its photophysical behaviour towards detection of various anions. The results showed that our receptor undergo ALE in >40% H2O-DMSO along with large pseudo Stokes shift (Delta lambda = 219 nm) and exhibit selective and sensitive detection towards hazardous cyanide's oxidation product, cyanate (CNO-) ion over other tested anions. The blue-shifted fluorescence emission (lambda(em) = 492 nm) enhancement with large Stokes shift (Delta lambda = 144 nm) was observed with the increase in cyanate concentration. The synthesized turn-on sensor towards cyanate detection could be applied in real sample analyses as an improvement to the method currently carried out by international standards and hereby a different approach has been made for the detection of cyanide through its oxidation form, cyanate. (C) 2020 Elsevier Ltd. All rights reserved.