The synthesis, structure and electrochemical properties of new cobalt and nickel complexes based on ferrocenyl-containing o-iminophenols

Synthesis, spectroscopic, electrochemical characterization, density functional theory (DFT), time dependent density functional theory (TD‐DFT), and antibacterial studies of some Co(II), Ni(II), and Cu(II) chelates of (E)‐4‐(1,5‐dimethyl‐3‐oxo‐2‐phenyl‐2,3‐dihydro‐1H‐pyrazol‐4‐yl)‐1‐(3‐hydroxynaphthalen‐2‐yl)methylene) thiosemicarbazide Schiff base ligand

“…The positive potential specifies that the metal in the lower oxidation state is strongly bound to the ligand, which indicates that the metal center has an equal attitude towards donor atoms. [ 83 ]…”

“…The positive potential specifies that the metal in the lower oxidation state is strongly bound to the ligand, which indicates that the metal center has an equal attitude towards donor atoms. [83] Ni(II) chelate 4 shows two irreversible oxidation peaks at E pa = 1.31 V and E pa = 1.52 V corresponding to the ligand moiety ( Figure 7). The chelate also exhibits one quasi-reversible redox wave, indicating that Ni(II) chelate undergoes Ni(II)/Ni(III) oxidation at E pa = 1.01 V and corresponding reduction at E pc = 0.84 V. [84] Extensive studies were reported on four coordinate Cu(II) chelates.…”

Heteroligand Metal Complexes with Extended Redox Properties Based on Redox-Active Chelating Ligands of o-Quinone Type and Ferrocene

“…An increase in the acceptor properties of redox-active o-quinonato-type ligands leads to an increase in the oxidation potentials of redox ligands as well as the following oxidation of ferrocenyl group(s). As a result, such a convergence The related cobalt(II) and nickel(II) bis-o-iminophenolates ( R L ON -Fc) 2 M II (M = Co or Ni), nickel(II) and copper(II) bis-o-iminophenolates ( R1R2 L ON -Fc) 2 M II (M = Ni or Cu) with ferrocenyl groups (Scheme 15) are reported in [104,105]. The crystalline structures of some of these complexes were established by XRD.…”

“…Complexes were synthesized by the reaction of the corresponding o-iminophenol with tin(II) chloride in the presence of a base. The related cobalt(II) and nickel(II) bis-o-iminophenolates ( R L ON -Fc)2M II (M = Co or Ni), nickel(II) and copper(II) bis-o-iminophenolates ( R1R2 L ON -Fc)2M II (M = Ni or Cu) with ferrocenyl groups (Scheme 15) are reported in [104,105]. The crystalline structures of some of these complexes were established by XRD.…”

“…Cobalt(II) bis-o-iminophenolates ( R L ON -Fc) 2 Co II react with o-benzoquinones with a one-electron oxidation of cobalt(II) to paramagnetic cobalt(III) o-semiquinone derivatives as, for example, ( R L ON -Fc) 2 Co III (3,6-DBSQ) (Scheme 16), which have well-resolved isotropic EPR spectra (g i = 2.000-2.001, a i (1 1 H) = 2.9 G, a i (1 1 H) = 3.7 G, a i ( 59 Co) = 11.3-11.5 G) [104].…”