Synthesis, Crystal Structure, and Thermal Decomposition Kinetics of Holmium With Benzoate and 2, 2'-Bipyridine Complex

Abstract

The complex [Ho(BA) 3 bipy] 2 (BA=benzoate; bipy=2,2′-bipyridine) was synthesized and characterized by elemental analysis, infrared spectra, ultraviolet spectra, single-crystal X-ray diffraction, thermogravimetry and differential thermogravimetry (TG-DTG) techniques. The crystal is monoclinic with space group P2 1 /n. The unit cell parameters are: a=14.1114(8) Å, b=15.3743(9) Å, c=25.8887(14) Å, β=103.555(2)°. Two Ho 3+ ions are connected by four carboxylic groups through a bridging bidentate mode. The thermal decomposition behavior of the title complex under nitrogenous atmosphere was studied using the TG-DTG, and IR techniques. The non-isothermal kinetics was investigated by using the Popescu method and the integral iso-conversional non-linear method (NL-INT). The mechanism function of the first decomposition step was determined. The thermodynamic parameters (ΔG ≠ , ΔH ≠ and ΔS ≠ ) were also calculated, and kinetic parameters (activation energy E and the pre-exponential factor A) were also obtained.