A series of lanthanide complexes with 2,3-dichlorobenzoic acid and 2,2:6′,2″-terpyridine: Crystal structures, spectroscopic and thermal properties

Abstract

Three new binuclear solid lanthanide complexes with the general formula [Ln(2,3-DClBA)3(terpy)(H2O)]2(Ln=Pr(1), Sm(2), Eu(3); 2,3-DClBA=2,3-dichlorobenzoate; terpy=2,2′:6′2″-terpyridine), have been synthesized and characterized. The powder XRD and single-crystal structures of the title complexes indicate that all the complexes are isomorphous. The two lanthanide ions in each complex are linked by two bridging bidentate carboxylate groups. Under ultraviolet light excitation, the europium complex exhibited characteristic red fluorescence of Eu3+(5D0→7F1–4). The thermal decomposition mechanism is investigated by TG/DSC–FTIR technology. The 3D stacked plots for the FTIR spectra of the evolved gases were recorded and the gaseous products were identified by the typical IR spectra obtained at different temperatures from the 3D stacked plots.