Temperature-dependent fluorescence quenching of a cavitand derivative by copper ions

Temperature dependence of fluorescence quenching of a cavitand derivative by Cu2+ ion has been studied in dimethylformamide solution. Results derived from PL studies highlighted two temperature regions where the formation of cavitand–Cu2+ complexes is based on significantly different molecular processes. From the experimental results and the comparison of the calculated interaction energies of the possible complex structures obtained by density functional calculations, it is assumed that at lower temperatures the Cu2+ ion takes place in the cavity while at higher temperature region Cu2+ is coordinated to the outer part of the cavitand with its almost retained solvation shell