Coordination modes of multidentate azodye ligand derived from 4,4′‐methylenedianiline towards some transition metal ions: Synthesis, spectral characterization, thermal investigation and biological activity

Synthesis and characterization of some binuclear metal complexes with a pentadentate azodye ligand: An experimental and theoretical study

A novel series of binuclear complexes with Mn(II), Co(II), Ni(II), Cu(II), Zn(II), and Cd(II) ions derived from a pentadentate azo dye ligand (H3L) was synthesized and structurally investigated by various physicochemical analyses, namely, scanning electron microscopy, transmission electron microscopy, NMR, UV–visible spectroscopy, and Electron‐Spin Resonance (ESR) studies. The infrared spectral data revealed characteristic bands due to ν(N=N) and ν(C=O) at 1606 and 1631 cm−1in the free ligand. However, their positions shifted and appeared at ~1564 and ~1592 cm−1on coordination, suggesting the involvement of carbonyl oxygen and azo nitrogen in complex formation. The spectral data suggested octahedral geometry for the complexes. The kinetic parameters such as order and activation energy were determined from the thermal decomposition values. X‐ray powder diffraction analysis showed the orthorhombic nature of the cadmium complex. Furthermore, Density functional theory (DFT) calculations were also recorded to describe the insight bonding. The synthesized compounds were tested forin vitroantibacterial activity againstK. aerogenes,S. aureus,B. acidoterrestris,E. coli,andV. choleraestrains by the cup‐plate method. In addition, the interactions that occurred in the protein–ligand complexes have been predicted by docking analysis.

Novel lanthanide(III) 4-methylbenzoylhydrazide complexes as precursors for lanthanide oxide nanophotocatalysts

A series of metal complexes were prepared from separate reactions of lanthanide nitrate salts (La(iii), Ce(iii), Sm(iii), Gd(iii) and Ho(iii)) with 4-methylbenzoylhydrazide. The structures of the complexes were confirmed by analytical studies, spectral measurements and thermal studies. Complexes were formed with different stoichiometries of 1 : 2 and 1 : 3 (M : L). The ligand chelates by the nitrogen and oxygen atoms of the amino and carbonyl groups of the hydrazide moiety in the neutral keto form. The coordination compounds were converted to metal oxide nanoparticles (MONPs) through solid state thermal decomposition as monocular source precursors. The obtained MONPs were investigated via XRD, TEM and UV-Vis spectra. As a representative, CeO₂ was utilized as a nanophotocatalyst to examine the photocatalytic activity of the MONPs for methylene blue (MB) photodegradation. CeO₂ showed high removal of MB dye by 90.1% after UV illumination for 220 min. The reported method provides a generalized and systematic method for the preparation of many metal oxide nanoparticles with manageable and reproducible features.

A series of metal complexes were prepared from separate reactions of lanthanide nitrate salts (La(iii), Ce(iii), Sm(iii), Gd(iii) and Ho(iii)) with 4-methylbenzoylhydrazide.