Electrochemical Synthesis of MII Complexes with a Schiff Base containing an Amido Group. Crystal Structure of a Cobalt(II) Complex with a Reorganised Ligand (original) (raw)
Related papers
Canadian Journal of Chemistry-revue Canadienne De Chimie, 2002
Ferrocenyl substituted ruthenium metallacyclic compounds, [Ru 2 (CO) 6 {l-g 1 :g 1 :g 2 :g 2 -1,4-Fc 2 C 5 H 2 O}] (1) and [Ru 2 (CO) 6 -{l-g 1 :g 1 :g 2 :g 2 -1,5-Fc 2 C 5 H 2 O}] (2) have been synthesized and structurally characterized. Electrochemical studies for 1 and 2 and the respective quinone derivatives 3 and 4 show weak to no electrochemical coupling at the mixed-valent intermediate state which is dependent on the complex frameworks.
2018
A series of six new mononuclear Schiff base complexes, <b>1</b>–<b>6</b> of cobalt(III) of the general formula, [CoLX] or its adduct with methanol, is reported. The pentadentate Schiff base ligand (H<sub>2</sub>L) was obtained by the condensation of <i>N</i>-(3-aminopropyl)-<i>N</i>-methylpropane-1,3-diamine with 1-(2-hydroxyphenyl)ethanone (H<sub>2</sub>L<sup>1</sup>) or 1-(2-hydroxyphenyl)propan-1-one (H<sub>2</sub>L<sup>2</sup>). X stands for the pseudohalides, N<sub>3</sub><sup>–</sup>, N(CN)<sub>2</sub><sup>−</sup> , and NCS<sup>–</sup>. The complexes have been synthesized by the reaction of equimolar amounts of cobalt(II) nitrate with H<sub>2</sub>L<sup>1</sup> or H<sub>2</sub>L<sup>2</sup> in the presence of the respective pseudohalide in methanol medium. All the ...
2007
The ruthenium(II)ecymene complexes [Ru(h 6 -cymene)(bha)Cl] with substituted halogenobenzohydroxamato (bha) ligands (substituents ¼ 4-F, 4-Cl, 4-Br, 2,4-F 2 , 3,4-F 2 , 2,5-F 2 , 2,6-F 2 ) have been synthesized and characterized by elemental analysis, IR, 1 H NMR, 13 C NMR, cyclic voltammetry and controlled-potential electrolysis, and density functional theory (DFT) studies. The compositions of their frontier molecular orbitals (MOs) were established by DFT calculations, and the oxidation and reduction potentials are shown to follow the orders of the estimated vertical ionization potential and electron affinity, respectively. The electrochemical E L Lever parameter is estimated for the first time for the various bha ligands, which can thus be ordered according to their electron-donor character. All complexes exhibit very strong protein tyrosine kinase (PTK) inhibitory activity, even much higher than that of genistein, the clinically used PTK inhibitory drug. The complex containing the 2,4difluorobenzohydroxamato ligand is the most active one, and the dependences of the PTK activity of the complexes and of their redox potentials on the ring substituents are discussed.
Synthesis, spectroscopy and electrochemistry of cobalt(III) Schiff base complexes
Journal of Chemical Research-s, 2005
The preparations and properties of bis complexes of ruthenium(i1) containing various combinations of the tridentate ligands 2,6-bis(pyrazol-l -ylmethyl)pyridine ( L1) and di-and tetra-methyl substituted derivatives (L2 and L3) are described. The absorption spectral properties of the complexes are thoroughly analysed. Full assignments have been made for the lH N M R spectra of two representative complexes in CD,CN and the origins of the co-ordination-induced shifts are discussed. Cyclic voltammetric experiments (MeCN solutions) reveal reversible one-electron Rul"-Ru" redox couples in the potential range 1 .OO-1.06 V vs. saturated calomel electrode (SCE). The occurrence of ligand-based irreversible reductions at low potentials (,EP,= values lie in the range: -1.90 to -2.20 V vs. SCE) reveals that these pyrazole-rich ligands are very poor n acceptors. The formal potentials of the RU"~-RU'' couples decrease (by ca. 8 mV per methyl group) a s the number of methyl groups in the ligands are increased. The decreased potential step size for [RuL(L')]'+ (L,L' = L1-L3) relative to those observed for non-sterically hindered ruthenium(i1) complexes reveals that in the present system steric effects due to 3-Me substituent(s) contribute to the observed effect but that electronic factors predominate over steric effects.
Inorganica Chimica Acta, 2013
Four new N 2 O 2 type tetradentate Schiff base complexes of Co(III), [Co(L x)(py) 2 ]PF 6 (CoL x , x = 1,3-4), and [CoNa(L 2)(py)(OAc)(CH 3 CH(OH)CH 3)(H 2 O)]ClO 4 Á(CH 3 CH(OH)CH 3), (CoNaL 2), where L x s are tetradentate Schiff base ligands derived from the condensation of meso-1,2-diphenyl-1,2-ethylenediamine (mesostilbenediamine) with salicylaldehyde derivatives, were synthesized and characterized by elemental analysis, 1 H NMR, IR, and UV-Vis spectroscopy. X-ray crystal structures of CoNaL 2 and CoL 3 were also determined. In CoNaL 2 , sodium atom is coordinated to CoL 2 moiety via two oxygen atoms of 3-OMe groups of salicylaldehyde part. A bridging acetate ion also has bridged the Co and Na centers. Cyclic voltammetry studies revealed that all of the complexes showed a one-electron reversible oxidation wave related to Co III/IV couple in the anodic region. Two reduction waves for Co III/II and Co II/I couples were also observed. The in vitro antimicrobial activity of the Schiff base complexes was tested against human pathogenic bacteria such as Salmonella typhi, Pseudomonas aeruginosa, Klebsiella pneumonia, Staphylococcus aureus and Listeria monocytogenes. All of the complexes showed moderate antibacterial activities against both Gram positive and Gram negative bacteria.