Synthesis, Crystal Structure, and Thermal Decomposition Kinetics of Six New Lanthanide Complexes

Six novel binuclear complexes have been reported in this paper: [Ln(2-Cl-6-FBA)2(5,5 '-DM-2,2 '-bipy)(NO3)]2, (Ln = Nd(1), Pr(2)); [Ln(2-Cl-6-FBA)3(5,5 '-DM-2,2 '-bipy)(H2O)]2, (Ln = Gd(3), Er(4), Eu(5), Ho(6); 2-Cl-6-FBA = 2-chloro-6-fluorobenzoate; 5,5 '-DM-2,2 '-bipy = 5,5 '-dimethyl-2,2 '-bipyridine). The complexes underwent comprehensive characterization, incorporating both elemental analysis and X-ray diffraction (XRD) methodologies. The subsequent X-ray single-crystal structure diffraction analysis illuminated the existence of diverse coordination characteristics within these complexes: the coordination number of complexes 1 and 2 is 9, and the coordination number of complexes 3-6 is 8. The fluorescence spectra of complex 5 were obtained by fluorescence test. The detailed decomposition processes of the six complexes were studied by TG-DTG-DSC/FTIR technique. The nonisothermal kinetics of complex 6 at the third step were discussed by using M. J. Starink method, NL-INT method, and double equal-double step method.