The coordination compounds of nickel with glycine and with an N-N ligand

1988 ◽  
Vol 53 (3) ◽  
pp. 563-570 ◽  
Author(s):  
František Březina ◽  
Zdeněk Šindelář ◽  
Jiří Kameníček ◽  
Jan Lasovský

The compounds [Ni(Gly)2N-N].nH2O (n = 1, 2; Gly = glycine anion; N-N – ethylenediamine 1,10-phenanthroline, α,α’-bipyridyl) and K[Ni(Gly)3].3H2O were prepared. On the basis of their magnetochemical and spectral properties, the compounds obtained can be characterized as octahedral nickel(II) complexes. Cyclic voltammetry was employed to study the redox properties of selected compounds and possible electrochemical and chemical oxidation were studied. The results obtained permitted comparison with the properties of nickel(II) complexes with dipeptides or tripeptides as ligands.

2005 ◽  
Vol 09 (01) ◽  
pp. 1-6 ◽  
Author(s):  
Igor V. Zhukov ◽  
Lyudmila A. Lapkina ◽  
Yuliya G. Gorbunova ◽  
Vladimir E. Larchenko ◽  
Aslan Yu. Tsivadze

Tris[tetra(15-crown-5)phthalocyaninato]dilutetium(III) ( R 4 Pc )3 Lu 2, whose structure had been confirmed earlier by X-ray analysis, was further examined by physicochemical studies. The redox properties of this complex were investigated by cyclic voltammetry. The spectroelectrochemical study of this compound has been performed for the first time. Based on the results obtained and analysis of literature data, an electrochemical criterion related to double- and triple-decker structure of lanthanide phthalocyanines has been proposed. IR and 1 H NMR data are also reported.


2002 ◽  
Vol 413 (1-2) ◽  
pp. 218-223 ◽  
Author(s):  
Hellas C.M Yau ◽  
Hing Leung Chan ◽  
Sen-fang Sui ◽  
Mengsu Yang

2008 ◽  
Vol 587-588 ◽  
pp. 109-113
Author(s):  
C. Teixeira ◽  
P. Parpot ◽  
Isabel Neves ◽  
António Maurício C. Fonseca

CoPAN complex has been entrapped in the supercages of Y zeolite and the redox properties of this zeolite-encapsulated complex were investigated by cyclic voltammetry with a new method for the preparation of carbon toray-zeolite-modified electrode. Formation of the CoPAN complex was ascertained by surface analysis (SEM, XRD), chemical analysis (CA), spectroscopy methods (FTIR and UV/vis) and cyclic voltammetry in aqueous medium with zeolite-modified electrodes. The cyclic voltammetry studies obtained with a zeolite-modified electrode shows evidence for electroactivity restricted to boundary associated CoPAN complex.


2013 ◽  
Vol 68 (5-6) ◽  
pp. 458-466 ◽  
Author(s):  
Iris Klawitter ◽  
Steffen Meyer ◽  
Serhiy Demeshko ◽  
Franc Meyer

Two methylene-bridged bis(imidazolium) salts [H4L1](PF6)2 and [H4L2](PF6)2 with appended amide groups have been synthesized which, after deprotonation, may serve as potentially tetradentate ligands providing two bis(imidazole-2-ylidene) and two amide donors. Using [H4L1](PF6)2, a square-planar nickel(II) complex [NiL1] and a six-coordinate bis(ligand) iron(II) complex [Fe(HL1)2] have been isolated and structurally characterized. Their low-spin states have been confirmed spectroscopically, and their redox properties have been studied by cyclic voltammetry. Oxidations are metal-centered to give NiIII and FeIII species, respectively


RSC Advances ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 6900-6918 ◽  
Author(s):  
Mouhieddinne Guergueb ◽  
Soumaya Nasri ◽  
Jihed Brahmi ◽  
Frédérique Loiseau ◽  
Florian Molton ◽  
...  

Preparation and UV/vis, IR, MS, 1H NMR, cyclic voltammetry and molecular structures of two new Co(ii) complexes with para-methoxy-phenyl and para-chloro meso-porphyrins and 4-cyanopyridine ligand (1–2). Catalytic oxidation data of MB dye using 1–2.


2014 ◽  
Vol 67 (3) ◽  
pp. 398 ◽  
Author(s):  
Peter Comba ◽  
Hubert Wadepohl ◽  
Arkadius Waleska

The solution coordination chemistry of iron complexes with the pentadentate bispidine ligands L1, L2, and L3 (dimethyl 9-oxo-2,4-di(pyridin-2-yl)-3,7-diazabicyclo[3.3.1]nonane-1,5-dicarboxylate derivatives) was examined. While in acetonitrile, (L1,2)FeII/III species have a preference for Cl– as co-ligand. The corresponding aqua and hydroxido complexes also prevail in the presence of Cl– in aqueous solution. The observed FeII/III potentials in water (cyclic voltammetry) and potentials of (L1–3)FeIV=O (buffered and unbuffered aqueous solutions) are strikingly similar, i.e. the latter are assigned to (L1–3)FeII/III potentials, and published potentials of FeIV=O complexes with other ligands with uncharged amine-pyridine donors, obtained by cyclic voltammetry, have to be considered with caution.


2013 ◽  
Vol 17 (01n02) ◽  
pp. 92-98 ◽  
Author(s):  
Pei-Shang Chao ◽  
Ming-Yu Kuo ◽  
Chen-Fu Lo ◽  
Min-Hsu Hsieh ◽  
Yu-Hsiang Cheng ◽  
...  

Zinc 5-(4-carboxy-phenylethynyl)-10,20-biphenylporphines bearing various substituents on the 10,20-phenyl rings are studied for their electrochemical and spectroelectrochemical properties. Cyclic voltammetry and optically transparent thin-layer electrochemical measurements suggest that the first reductions of these porphyrins should be the reduction reaction of the carboxylic protons. For the porphyrin ring reactions, our study shows that the redox properties can be significantly affected by the alkoxyl chains on the 10,20-phenyl rings.


2004 ◽  
Vol 70 (1) ◽  
pp. 52-60 ◽  
Author(s):  
Ronald S. Oremland ◽  
Mitchell J. Herbel ◽  
Jodi Switzer Blum ◽  
Sean Langley ◽  
Terry J. Beveridge ◽  
...  

ABSTRACT Certain anaerobic bacteria respire toxic selenium oxyanions and in doing so produce extracellular accumulations of elemental selenium [Se(0)]. We examined three physiologically and phylogenetically diverse species of selenate- and selenite-respiring bacteria, Sulfurospirillum barnesii, Bacillus selenitireducens, and Selenihalanaerobacter shriftii, for the occurrence of this phenomenon. When grown with selenium oxyanions as the electron acceptor, all of these organisms formed extracellular granules consisting of stable, uniform nanospheres (diameter, ∼300 nm) of Se(0) having monoclinic crystalline structures. Intracellular packets of Se(0) were also noted. The number of intracellular Se(0) packets could be reduced by first growing cells with nitrate as the electron acceptor and then adding selenite ions to washed suspensions of the nitrate-grown cells. This resulted in the formation of primarily extracellular Se nanospheres. After harvesting and cleansing of cellular debris, we observed large differences in the optical properties (UV-visible absorption and Raman spectra) of purified extracellular nanospheres produced in this manner by the three different bacterial species. The spectral properties in turn differed substantially from those of amorphous Se(0) formed by chemical oxidation of H2Se and of black, vitreous Se(0) formed chemically by reduction of selenite with ascorbate. The microbial synthesis of Se(0) nanospheres results in unique, complex, compacted nanostructural arrangements of Se atoms. These arrangements probably reflect a diversity of enzymes involved in the dissimilatory reduction that are subtly different in different microbes. Remarkably, these conditions cannot be achieved by current methods of chemical synthesis.


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