Triazole-Linked Anthracenyl-Appended Calix[4]arene Conjugate As Receptor for Co(II): Synthesis, Spectroscopy, Microscopy, and Computational Studies

A new triazole-linked anthracenyl-appended calix[4]­arene-1,3-diconjugate (<b>L</b>) has been synthesized and characterized, and its single crystal XRD structure has been established. Binding properties of <b>L</b> toward different biologically relevant metal ions have been studied by fluorescence and absorption spectroscopy in ethanol. <b>L</b> exhibits selective recognition of Co²⁺ and can detect down to a concentration of 55 ppb (0.92 μM). The roles of the calix[4]­arene platform as well as the preorganized binding core in <b>L</b>’s selective recognition have been demonstrated by studying appropriate control molecules. The mode of binding of <b>L</b> with Co²⁺ has been modeled both by DFT and MD computational calculations. <b>L</b> and its Co²⁺ complex could be differentiated on the basis of the nanostructural features observed in AFM and TEM