Synthesis, spectral, optical and anti-inflammatory activity of complexes derived from 2-aminobenzohydrazide with some rare earths

Three new metal complexes derived from Er(III), Dy(III) and Zr(IV) with 2-aminobenzohydrazide (ABH) were synthesized and characterized by elemental analyses, IR, H-1-NMR, ES-MS and transmission electron microscopy (TEM). The morphology and the particle size were determined by TEM. The results showed that the ligand acted as neutral bi-dentate coordinating to the metal ions through the carbonyl oxygen and amidic amino nitrogen. The aromatic amine group remained inert towards coordination. The optical band gap was measured and found to be 3.3, 3.5 and 4.3 eV for Er(III), Dy(III) and Zr(IV), respectively. The optical band gap values indicated a semi-conducting nature of the investigated complexes. The anti-inflammatory and analgesic activities of the tested compounds were determined and compared with standard meloxicam.