The coordination chemistries of the tetradentate N2O2-type ligands N-(2-pyridylmethyl)iminodiethanol (H2pmide) and N-(2-pyridylmethyl)iminodiisopropanol (H2pmidip) have been investigated with nickel(ii) and cobalt(ii/iii) ions. Three novel complexes prepared and characterized are [(Hpmide)2Ni3(CH3COO)4] (1), [(Hpmide)2Co3(CH3COO)4] (2), and [(pmidip)2Co3(CH3COO)4] (3). In 1 and 2, two terminal ...

Metal-dioxygen adducts are key intermediates detected in the catalytic cycles of dioxygen activation by metalloenzymes and biomimetic compounds. In this study, mononuclear cobalt(III)-peroxo complexes bearing tetraazamacrocyclic ligands, [Co(12-TMC)(O(2))](+) and [Co(13-TMC)(O(2))](+), were synthesized by reacting [Co(12-TMC)(CH(3)CN)](2+) and [Co(13-TMC)(CH(3)CN)](2+), respectively, with H(2)O...

The nitrite ® nitro isomerization in nitritopentaamine cobalt (III) halides has been known. In this paper, the effect of the size of the counter ions (noncoordinated groups) on the rate of isomerization in nitritopentaamine cobalt (III) halides, is reported. The rate of isomerization is decreased by increasing the size of the counter ions. This decrease is explained on the...

Zinc finger domains are structures that mediate sequence recognition for a large number of DNA-binding proteins. These domains consist of sequences of amino acids containing cysteine and histidine residues tetrahedrally coordinated to a zinc ion. In this report, we present a means to selectively inhibit a zinc finger transcription factor with cobalt(III) Schiff-base complexes. 1H NMR spectrosco...

The paper is devoted to the development of a method for obtaining and using iron-containing sorption materials effective removal arsenic compounds different oxidation states from an aqueous medium. It known that have harmful effect on biota due high toxicity. theoretically experimentally substantiates choice as main sorbent material A series adsorbents, including powder, activated carbon-based ...

Speciation studies of cobalt species, cobalt (II) and cobalt (III) have been carried out using spectrophotometric determination with the chromophoric reagent bis (5-bromosalicylaldehyde) orthophenilinediamine (BBSOPD). The methodology is direct and non extractive and is carried out in 40% ethanolic medium containing acetate buffer. The colour development is almost instantaneous and remained con...

Highly reactive tris-carbene Co(I) complexes [(TIMENaryl)Co]Cl react with organic azides to yield monomeric Co(III) imido complexes [(TIMENaryl)Co(NAr')](BPh4) (aryl = mes, xyl; Ar = -C6H4-CH3, -C6H4-OCH3). The cobalt-imido fragment in these complexes is electrophilic and, as a result, the imido group readily inserts into the cobalt-carbene bond, yielding bis-carbene imine cobalt complexes.

Cobalt-mediated radical polymerisation of methyl acrylate is effected at moderate temperature by both a square planar bis(beta-ketoaminato)cobalt(II) complex in the presence of V-70 diazo radical initiator, and by a well-defined cobalt(III) alkyl derivative in the absence of a diazo complex. Polymerisation rates suggest that both reversible termination and degenerative transfer mechanisms are o...

Institut Agronomique, Universit6 de Louvain, H~verl6-Louvain (Belgium) ABSTRACT MO~TTMOm~LLONrrE may adsorb cobalt(III)hexammine and cobalt(III)chloropentammine cations, and the C.E.C. determined for these complex cations is of the order of magnitude of that obtained with ammonium. The infrared spectra of these coordination complexes adsorbed by the clay are similar to those observed for the co...