Syntheses, characterization, luminescence, and thermal decomposition mechanism of four lanthanide complexes with 4-ethylbenzoic acid and terpyridine

• Published in: Journal of thermal analysis and calorimetry Vol. 124; no. 3; pp. 1575 - 1585
• Main Authors: Huo, Jian-Xia, Wang, Ye, Zhang, Da-Hai, Ren, Ning, Zhang, Jian-Jun
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.06.2016; Springer
• Subjects: Analysis; Analytical Chemistry; Binding; Calorimetry; Chemical properties; Chemistry; Chemistry and Materials Science; Diffraction; Fragments; Inorganic Chemistry; Lanthanides; Ligands; Luminescence; Measurement Science and Instrumentation; Physical Chemistry; Polymer Sciences; Rare earth metals; Thermal decomposition; Thermal properties; X-rays; Thermal analysis; 2,2′:6′,2′′-Terpyridine; Lanthanide complexes; Luminescence; Crystal structure
• ISSN: 1388-6150; 1588-2926; 1572-8943
• DOI: 10.1007/s10973-016-5266-4

Four new lanthanide 4-ethylbenzoic acid complexes [Ln(4-EBA) 3 (terpy)H 2 O] 2 {Ln = Sm(1), Eu(2), Tb(3), Dy(4), 4-EBA = 4-ethylbenzoate, terpy = 2,2′:6′,2′′-terpyridine} have been synthesized. The complexes are characterized by means of elemental analysis, IR, UV, and XRD. The crystals [Ln(4-EBA) 3 (terpy)H 2 O] 2 {Ln = Eu(2), Tb(3)} are characterized by single-crystal X-ray diffraction. These complexes feature a tridentate terpyridine ligand, 4-ethylbenzoic acid ligands exhibiting multiple binding modes, bidentate, bridging bidentata, and monodentate, and a bound water molecule. The Ln 3+ ions have a typical coordination number of nine with a distorted monocapped square antiprism. The thermal decomposition mechanism of the complexes has been investigated by TG/DSC–FTIR technology, and IR spectra of the evolved gases show complexes broken down into H 2 O, CO 2 , and other gaseous molecules as well as the gaseous organic fragments. Moreover, the complexes [Ln(4-EBA) 3 (terpy)H 2 O] 2 exhibit characteristic luminescence, indicating that ligands can act as sensitizing chromophore in these systems.