Complexes of Er(III), Gd(III), and La(III) with (2E,15E)-2-[1-(2-aminophenyl)ethylidineamino]-N′-[1-(2-aminophenyl)ethylidene]benzoic acid hydrazide (AEBH) have been synthesized. The isolated complexes were characterized by elemental analyses, thermal analyses (TGA, DTA), IR, 1H NMR, 13C NMR, ES-MS, TEM, and conductance measurements. The results indicated that the ligand coordinates to La(III), Gd(III), and Er(III) in the keto form as neutral pentadentate ligand. The particle size and morphology have been determined by TEM. In vivo pharmacological evaluation of the synthesized compounds in collagen II—Freund’s adjuvant model proved the presence of anti-inflammatory and analgesic activities of these compounds. Gd(III) complex showed higher effect in comparison with the well-known drug meloxicam.
Graphical Abstract