Morphological, structural, and photophysical properties of luminescent coordination compounds based on Eu3+and a zwitterionic ligand: A theoretical and experimental investigation

The development of functional materials with photoluminescent properties based on coordination compounds and trivalent lanthanide ions has attracted interest from the scientific community. In this regard, two materials based on a combination of zwitterion ligand (3-(1-methylimidazolium-1-yl) butane-1-sufonate) (Z) and Eu3+ ions (EuZCrystal and EuZGel) were prepared by a simple and efficient method, and the chemical, morphological, and photophysical properties were evaluated. Nuclear Magnetic Resonance (NMR) analysis reveals a broadening and shift from EuZCrystal and EuZGel spectra relative to the Z ligand, especially for the S-O bond, which indicated that the sulfone group is the coordinating site responsible for the bond between the Z molecule and Eu3+. The emission spectra reveal the line profiles of the Eu3+ ion in the coordination compounds for EuZCrystal and EuZGel, which agree with the formation of the new luminescent material. Although the ligand & RARR; Eu3+ energy transfer rates are at least 100 times higher than the rates calculated for the Eu3+ & RARR; Eu3+ energy transfer, the experimental excitation spectrum suggests that there is not enough electron population to populate the 5D0 emitter state and its consequent decay.