Synthesis, crystal structure, luminescence and thermal decomposition kinetics of Eu(III) complex with 2,4-dichlorobenzoic acid and 2,2′-bipyridine

Abstract

The complex of [Eu(2,4-DClBA) 3(bipy)] 2 (2,4-DClBA = 2,4-dichlorobenzoate; bipy = 2,2′-bipyridine) was obtained and characterized by elemental analysis, IR spectra, UV spectra, luminescence spectra, 1H NMR spectra, single crystal X-ray diffraction and TG–DTG techniques. Two Eu 3+ ions are connected by four carboxylate groups through bridging bidentate and bidentate chelating-bridging mode. The coordination number of europium ion is nine. The thermal decomposition behavior of the title complex under a static air atmosphere can be discussed by TG–DTG, SEM and IR techniques. The non-isothermal kinetics was investigated by using double equal-double steps method and Starink method. The mechanism function of the first decomposition step was determined. Meanwhile, the thermodynamic parameters (Δ H ≠, Δ G ≠ and Δ S ≠) and kinetic parameters (activation energy E and the pre-exponential factor A) were also calculated.