Ligand-controlled UV light absorption property and neuromorphic behavior of a new Th(IV)- bisphosphoramide complex

Abstract

This article describes the synthesis and photophysical properties of a new furan-based bisphosphoramide ligand (L) and its Th(IV) complex characterized by various analytical and spectroscopic techniques. As expected, L, associated with several double bonds within the structure and the possible π → π* transitions, displays strong absorption in the UV region. Notably, the absorption of UV light decreases significantly in an exclusive manner for the L-Th4+ complex, and such behavior was not observed with most of the transition metals as well as f-metal ions. The ligand-to-metal binding ratio of L-Th4+ was found to be 1:1 through the Job’s plot. This photophysical property was successfully explored in the selective determination of Th4+ ions in aqueous solutions. The limit of detection (LOD) for Th4+ and limit of quantitation (LOQ) were determined to be 1.04 x 10-7 M and 3.472 x 10-7 M, respectively. In order to get an insight at the molecular level, a density functional theory (DFT) investigation was performed to comprehend the sensing mechanism and interaction in the detection of Th4+ by L. Furthermore, this salient UV light absorption phenomenon was employed in exploring the artificial synaptic behavior of the L-Th4+ complex which can have remarkable memory and applications in neuromorphic devices.