Abstract
Ru3+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+ uni-metallic complexes of dihydrazone derived from the condensation of 3-hydrazonoindolin-2-one with 4-formyl antipyrine were synthesized. The resulted dihydrazone and its chelated compounds structurally characterized basing on spectroscopic tools (NMR, FT-IR, EAS, ESI-MS) thermo-gravimetric, elemental, magnetic and molar conductance measurements. This structural elucidation leads us to conclude that the dihydrazone has been performed as a neutral bidentate chelator linked the Ru3+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+ ions via the carbonyl and azomethine of isatin moiety adopting regular or distorted octahedral structures around the central metallic ions. The structural description of dihydrazone and its chelated compounds have been endorsed basing on the Density Functional Theory calculations. The optimized geometry, global reactivity descriptors, and LUMO-HOMO orbitals and of the molecules have been calculated by the DFT-B3LYP method and 6e311G(d,p) basis set. The molecular electrostatic potential picture has been painted utilizing the same level of theory to envision the molecules charge distribution and chemical reactivity. The DFT studies of the designated compounds revealed small HOMO-LUMO gap which is a strong indication to the large reactivity these compounds. The TG analysis has confirmed the complexes chemical formulae and assured that the thermo-degradation processes occur in three or four steps ended with the formation of metal oxide or carbon-contaminated metal oxide residues. The In-vitro antibacterial of dihydrazone and its chelated compounds have been evaluated against E. coli, P. aeruginosa, K. pneumonia and B. subtilis, the observed antibacterial result denoted that Cu2+ and Zn2+ complexes have a good activity in comparation with the free dihydrazone. (C) 2021 Elsevier B.V. All rights reserved.