Synthesis and Appraisal of Anion‐Binding Studies in One‐Walled Meso ‐Superpyrrolyl‐Extended Calix[4]Pyrroles

Abstract In this investigation, we have designed and constructed two new one‐walled superpyrrolyl‐extended calix[4]pyrrole‐based receptors by the virtue of the Clauson–Kaas and Paal–Knorr protocols as key steps. Thus, fabricated receptors were wholly characterized by means of typical spectroscopic practices such as 1 H‐NMR, 13 C‐NMR, and mass spectrometry. After systematic characterization, both the receptors were probed for their anion binding studies toward diverse anions, for instance, spherical, trigonal, tetrahedral, and linear, used as tetrabutylammonium (TBA) salts, by means of UV–vis spectrophotometric titrations in solution phase. From the data analysis, 1:1 anion binding stoichiometries were observed upon non‐linear curve fitting using an online BindFit v0.5 software, which were further validated through the Job's plots. To our expectation, amongst all the studied anions, the maximum binding affinity was perceived for fluoride anion with both the receptors, due to its smaller size and strong hydrogen bonding capacity.