Crystal structures, spectroscopic, and thermal properties of Dysprosium (III) and Europium (III) complexes with 3-chloro-4-methoxybenzoic and 1,10-phenanthroline

Abstract

Two lanthanide complexes with the formula [Dy(3-Cl-4-MOBA)3phen]2 (1) and [Eu (3-Cl-4-MOBA)3phen]2 (2) (3-Cl-4-MOBA=3-chloro-4-methoxybenzoate; phen=1,10-phenanthroline) were synthesized and characterized by elemental analysis, molar conductivity, ultraviolet spectra, infrared spectra, single crystal X-ray diffraction, and thermal analysis. The two complexes are isostructural. Two lanthanide cations are connected by four carboxylic groups through a bridging bidentate mode, resulting in distorted square-antiprism geometry. Under the excitation ultraviolet light, the two complexes exhibit characteristic emission of dysprosium or europium cation. The gaseous decomposition products of the two complexes were inferred by thermogravimetry and infrared spectrometry techniques. The heat capacity of the complexes was measured using differential scanning calorimetry technology. And the thermodynamic functions including entropy, gibbs free energy, and enthalpy relative to the reference temperature (298.15 K) were also calculated. In addition, the antifungal activities of the two complexes were also studied.