Five Dinuclear Lanthanide Complexes Based on 2,4-dimethylbenzoic Acid and 5,5'-dimethy-2,2'-bipyridine: Crystal Structures, Thermal Behaviour and Luminescent Property

Jia-Yuan Zhao; Ning Ren; Ying-Ying Zhang; Kun Tang; Jian-Jun Zhang

doi:10.3389/fchem.2021.726813

Five Dinuclear Lanthanide Complexes Based on 2,4-dimethylbenzoic Acid and 5,5'-dimethy-2,2'-bipyridine: Crystal Structures, Thermal Behaviour and Luminescent Property

Front Chem. 2021 Oct 18:9:726813. doi: 10.3389/fchem.2021.726813. eCollection 2021.

Authors

Jia-Yuan Zhao¹, Ning Ren², Ying-Ying Zhang³, Kun Tang⁴, Jian-Jun Zhang¹

Affiliations

¹ College of Chemistry and Materials Science, Testing and Analysis Center, Hebei Normal University, Shijiazhuang, China.
² Hebei Key Laboratory of Heterocyclic Compounds, College of Chemical Engineering and Material, Handan University, Handan, China.
³ Hengshui No.1 High School, Hengshui, China.
⁴ Huaxin College of Hebei Geo University, Shijiazhuang, China.

Abstract

A series of new complexes, [Ln (2,4-DMBA)₃(5,5'-DM-2,2'-bipy)]₂ (Ln = Sm(1), Eu (2)), [Pr (2,4-DMBA)₃ (5,5'-DM-2,2'-bipy)]₂·0.5(C₂H₅OH) (3), [Ln (2,4-DMBA)₃ (5,5'-DM-2,2'-bipy)]₂·0.5(2,4-DMBAH)·0.25(5,5'-DM-2,2'-bipy) (Ln = Tb (4), Dy (5)) (2,4-DMBA = 2,4-dimethylbenzoate, 5,5'-DM-2,2'-bipy = 5,5'-dimethy-2,2'-bipyridine) were synthesized via hydrothermal reaction conditions. The complexes were characterized through elemental analysis, Infrared spectra (IR), Raman (R) spectra, UV-Vis spectra, single X-ray diffraction. Single crystal data show that complexes 1-5 are binuclear complexes, but they can be divided into three different crystal structures. The thermal decomposition mechanism of complexes 1-5 were investigated by the technology of simultaneous TG/DSC-FTIR. What's more, the luminescent properties of complexes 1-2 and 4 were discussed, and the luminescence lifetime (τ) of complexes 2 and 4 were calculated.

Keywords: TG/DSC-FTIR; aromatic carboxylic acids; crystal structure; lanthanide complexes; luminescence.