3‑(Dicyanomethylidene)indan-1-one-Functionalized Calix[4]arene–Calix[4]pyrrole Hybrid: An Ion-Pair Sensor for Cesium Salts

A chromogenic calix[4]­arene–calix[4]­pyrrole hybrid ion pair receptor bearing an indane substituent at a β-pyrrolic position has been prepared. On the basis of solution-phase UV–vis spectroscopic analysis and 1H NMR spectroscopic studies carried out in 10% methanol in chloroform, receptor 1 is able to bind only cesium ion pairs (e.g., CsF, CsCl, and CsNO3) but not the constituent cesium cation (as its perchlorate salt) or the F–, Cl–, or NO3– anions (as the tetrabutylammonium salts). It thus displays rudimentary AND logic gate behavior. Receptor 1 shows a colorimetric response to cesium ion pairs under conditions of solid–liquid (nitrobenzene) and liquid–liquid (D2O–nitrobenzene-d5) extraction.