A series of 3D lanthanide complexes based on H bond and halogen-halogen interactions:Synthesis,structure, spectroscopic and thermal properties

Four lanthanide coordination complexes, namely, Ln(2,3-DClBA)_3(5,5'-dmebipy)(H_2O)]_2(Ln=Sm(1), Eu(2), Dy(3), Ho(4)); 2,3-DClBA=2,3-dichlorobenzoate; 5,5'-dmebipy=5,5'-dmethylbipyridine) were synthesized and characterized by elemental analysis, infrared spectroscopy and single crystal X-ray diffraction. Findings indicated that complex 3 was a dinuclear molecule, and the center Dy~(3+) was eight-coordinated. Each dinuclear units could be connected by H bond and halogen-halogen interactions. Luminescent property of complex 2 suggested the typical intense emissions of Eu~(3+) ions. Thermal analysis showed that the complexes decomposed in three steps: the coordination water was lost firstly then the neutral ligand 5,5'dmebipy was lost and lastly the 2,3-DClBA ligand was lost.