Synthesis and characterization of Fe(II)- and Cr(II)-complexes with isatin-aryl hydrazone ligand as bio-reactive reagents and effective catalysts for styrene epoxidation.

For the facile preparative description of aryl-hydrazones and their interesting coordination modes, a new aryl-hydrazone derivative (HLhdzh) was formed from the combination of 2,4-dihydroxybenzaldehyde with isatin-hydrazide. HLhdzh coordinated to Fe2+ and Cr2+ ions to give two new metal(II)-complexes (as Fe(Lhdzh)2 and Cr(Lhdzh)2, respectively). Their chemical structure was confirmed with perspective spectroscopic tools, and by measuring their purity via micro-elemental investigations. Against the proliferative progress of human cancer cell lines and the namely prevalent microbial series, the bio-potential of HLhdzh, Fe(Lhdzh)2, and Cr(Lhdzh)2 was demonstrated, highlighting the considerable action of the nuclearity in Fe(Lhdzh)2 and Cr(Lhdzh)2 compared to that of HLhdzh. Also, the bio-potential of HLhdzh, Fe(Lhdzh)2, and Cr(Lhdzh)2 was studied within their interacting process with ctDNA (deoxyribonucleic acid) spectrophotometrically and viscometrically. Their antireflective action against the tumors and microorganisms was successfully reported, within the inhabited zoon areas (against the microbes) and the IC50 concentrations (against the tumors). Assigning the values of Gibbs' free energy and binding constant, the nature of their interacting features was addressed, referring to the presented mono-nuclear ion (nuclearity effect) for modification of their complexes' interaction. For the catalytic oxygenative systems, the homogeneous catalytic potential of Fe(Lhdzh)2 and Cr(Lhdzh)2 was evaluated in the oxygenative progress of styrene with H2O2 to give styrene-epoxide at 85 °C. The yield percentage of styrene-epoxide catalyzed by Fe(Lhdzh)2 or Cr(Lhdzh)2 was obtained using GC-MS, affording 88 and 85 % after 5 h, respectively. The reactivity variation for each catalyst was attributed to the influence of nuclear nature (synergistic influence), which was supported by a proper mechanism, spectroscopically.