Supramolecular of lanthanide-2,6-dimethylbenzoic acid-2,2′:6′,2″-terpyridine materials: Crystal structures, luminescent property, and thermochemical behaviour

Abstract

Three mononuclear complexes [Ln(2,6-DMBA)3(terpy)] (Ln = Dy(1), Ho(2), Er(3); 2,6-DMBA = 2,6-dimethylbenzoate; terpy = 2,2′:6′,2″- terpyridine) were synthesized via conventional solution method and characterized by elemental analysis, IR spectra, thermal analysis and single X-ray diffraction techniques. The single-crystal X-ray structures of complex 1–3 are described here, and the complexes are isomorphous and crystallize in the orthorhombic crystal system Pbcn space group. Each Ln(III) ion is nine-coordinated by six O atoms from three 2,6-DMBA ligands and three N atoms from a terpy molecule, which is defined as a distorted monocapped square anti-prismatic geometry. Each adjacent Ln(III) structural unit forms a 2D supramolecular structure through CH⋯O intermolecular hydrogen bonding interaction. The thermal decomposition mechanism of complexes 1–3 were analyzed by TG/DSC-FTIR. The luminescence spectra of Dy(III) complex were studied and the characteristic emission peaks of Dy(III) ion were observed.