Metal ion induced changes in the structure of Schiff base hydrazone chelates and their reactivity effect on catalytic benzyl alcohol oxidation and biological assays

Divalent para-magnetic copper(II) and iron(II) chelates of Schiffbase isatin hydrazone derivative are synthesized and characterized, as CuLONOCl and Fe(LONO)(2), respectively. With different stoichiometric ratios (molar ratios) of 1: 1 and 1: 2 of Cu2+ or Fe2+ ion to the ligand (HLONO), both chelates are prepared with distorted square planar and octahedral structures, respectively. The catalytic action of both CuLONOCl and Fe(LONO)(2) is examined in the homogeneous oxidation benzyl alcohol using H2O2 to benzaldehyde (the selective product). All studied compounds involved in the antimicrobial and anticancer studies and also against the ctDNA. Catalytically, their optimization is progressed within the influence of temperature, time and solvent. CuLONOCl manifests an optimized catalytic atmosphere for the yield percentage of benzaldehyde (92%) at 70 degrees C after 4 h, whereas, Fe(LONO)(2) displays less catalytic action with less yield (88%) after 3 h at 90 degrees C. The variation in their structure and central metal ion assign to understand the difference in their catalytic potentials. The proposed mechanism for the oxygenation process based on electron-oxygen transfer steps. In the biological studies, CuLONOCl displays more action against some common microbes (bacteria and fungi) and cancers growth compared to that of Fe(LONO)(2). The role of M2+ ion in its complex and its geometries illustrate their utility in such biological studies within Tweedy's chelation theory. Their interaction with ctDNA (calf thymus DNA) is aimed to represent the impact of Cu2+ and Fe2+ ions in the complexing agents with the influence of their structures through the changes and shifts of spectroscopic the viscosity investigations. Their interaction with ctDNA is illustrated spectroscopically according to the derived values of the binding constants, K b, and the negative Gibbs' free energy, Delta G(b)'-. (C) 2022 Elsevier B.V. All rights reserved.

Automated summary

Divalent para-magnetic copper(II) and iron(II) chelates of Schiffbase isatin hydrazone derivative are synthesized and characterized. CuLONOCl and Fe(LONO)(2) exhibit distorted square planar and octahedral structures, respectively. Both chelates show catalytic activity in the oxidation of benzyl alcohol, with CuLONOCl displaying higher yields of benzaldehyde and Fe(LONO)(2) exhibiting less catalytic action. CuLONOCl also demonstrates stronger antimicrobial and anticancer effects compared to Fe(LONO)(2). The interaction of these chelates with ctDNA is studied spectroscopically.