Preparation, characterization and properties of four new trivalent lanthanide complexes constructed using 2-bromine-5-methoxybenzoic acid and 1,10-phenanthroline

Abstract

Four dinuclear trivalent lanthanide complexes of the general formula [Ln2(2-Br-5-MOBA)6(phen)2] (Ln = Nd(), Sm(), Ho(), Er(); 2-Br-5-MOBA = 2-bromine-5-methoxybenzoate, phen = 1,10-phenanthroline) were prepared and structurally characterized. The complexes to are isostructural with a coordination number of nine. The carboxylic acid ligands adopt bridging, bidentate chelating, and tridentate chelating bridging modes to coordinate with Ln(iii) ions. The structures of the complexes were confirmed on the basis of elemental analysis, molar conductance, thermogravimetric analysis (TGA), and IR and UV spectra. The heat capacities and thermal circulating processes of the prepared complexes were performed on a differential scanning calorimeter under a nitrogen atmosphere. Two remarkable solid-solid phase transitions existed both in the heat capacities and thermal circulating processes. The bacteriostatic activities of the complexes were evaluated against Candida albicans, Escherichia coli and Staphylococcus aureus. Besides, the luminescent property of complex was also investigated, and the magnetic properties of complexes and were also discussed in detail.

Crystal structures, thermal decomposition kinetics and thermodynamic properties of lanthanide Ho(III) complex with 2,5-dichlorobenzoic acid and 5,5′-dimethyl-2,2′-bipyridine

“…本课题组一直 致力于稀土羧酸配合物的合成及其性能的研究. 2015 年, 宗广才 [17] 以2-溴-5-甲氧基苯甲酸和1,10-邻菲罗啉 为配体与稀土离子合成了系列稀土配合物, 并对其中 Ho(III)和Er(III)配合物进行了磁性研究. 2017年, 申盼 盼 [18] 通过使用有机羧酸和5,5′-二甲基-2,2′-联吡啶合成 了系列稀土配合物, 并进行了抑菌活性测试, 结果显示 此类配合物对白色念珠菌具有很好的抑制作用.…”

Lanthanide Complexes with 2,3-Dimethoxybenzoic Acid and Terpyridine: Crystal Structures, Thermal Properties, and Antibacterial Activities

“…The band assigned to the vibration of ν s (COO–) are observed at 1421 and 1420 cm –1 respectively. Meanwhile, the bands occurring in the region 419 cm –1 , ν( Ln –O), for the complexes indicate that oxygen atoms of the carboxyl groups participate in coordination with the Ln III ion , . Furthermore, there are characteristic bands at 1580 cm –1 for ν(C=N), 746 and 831 cm –1 for δ(C–H) of the 2,2′:6′,2′′‐terpyridine group, which shifted to higher wavenumbers of 1624, 1616, 772–779, and 853 cm –1 , respectively, indicating that the nitrogen atoms of terpy are coordinated to the rare earth ion, which was confirmed by structural analyses.…”

Effect of synthesized temperature on the assembly and properties of four lanthanide supramolecular frameworks

“…Beyond that trivalent lanthanide ions are outstanding in fluorescence applications because of their high color purity due to the 4f-shell electronic transitions [8]. Benzoic acid and some of its derivatives are often used as catalyst precursor polymers in pharmaceutical industries, and important organic ligands to construct complexes with lanthanide metal ions [9].…”