Synthesis and experimental/theoretical evaluation of an efficient Calix[4]arene based sensor for selective detection of Pt2+ ion

In this study, a novel derivative of functionalised Calix[4]arene chem-sensor (4-amino thiazole 2-thiol-Calix[4]arene (R-Sensor)) was investigated, using the FT-IR spectroscopic method. Fluorescent properties and the ability to detect the sensor toward different cation ions in acetonitrile aqueous solution were investigated using the UV-Vis method, fluorescence titration, and Job's plot method. The results showed that among the studied cations, the presence of Pt(II) has a greater effect on the intensity and wavelength of the emission. In addition, the optimised structure and electronic properties of this R-sensor was studied, using the density functional theory (DFT), B3LYP and M062X methods, at the LANL2DZ (6-311 (+ )G/CPCM and 6-311(++)G/CPCM) basis set, and quantum theory of atoms in molecules (QTAIM). The results of these theoretical-computational studies showed that the selectivity of this sensor is related to its molecular structure, electronic properties, and surface electrostatic properties. Theoretical studies have shown that electronic properties such as energy gap, sensitivity, and charge/energy transfer change dramatically in the presence of Pt(II) cations. In addition, the molecular competitive tests showed that this R-sensor could be a good candidate for monitoring/measuring Pt(II) in physiological samples/ environments.