A series of lanthanide complexes with different aromatic carboxylic acid ligands: Synthesis, supramolecular structure, thermal properties and luminescence behaviors

Six noble two-dimensional lanthanide complexes [Ln(2,4-DFBA)3(terpy)·H2O]·H2O (Ln = Tb(1), Dy(2)), [Pr(2,4,6-TMBA)3(terpy)·H2O] (3) [Nd(2,4,6-TMBA)3(terpy)·H2O]·C2H5OH·H2O(4) and [Ln(2,4,6-TMBA)3(terpy)·H2O]·1.5H2O (Ln = Dy(5), Ho(6) (2,4-DFBA = 2,4-difluorobenzoate, 2,4,6-TMBA = 2,4,6-trimethylbenzoate, terpy = 2,2 ': 6′, 2 ''- terpyridine) were synthesized by conventional solution method with 2,4-difluorobenzoic acid and 2,4,6-trimethylbenzoic acid as main ligands and 2,2 ': 6′, 2 ''- terpyridine as auxiliary ligands. The complexes were characterized by infrared spectroscopy and Raman spectroscopy, and the thermal decomposition mechanism of the complex was studied by TG-DTG-DSC/FTIR coupling technology. The solid fluorescence test was also carried out for complexes 1,2 and 4. It was found that the complexes have good fluorescence properties, and the fluorescence lifetime of complex 1 was 0.541 ms.