Redox Properties of Iron Complexes with Pentadentate Bispidine Ligands

2014 ◽  
Vol 67 (3) ◽  
pp. 398 ◽  
Author(s):  
Peter Comba ◽  
Hubert Wadepohl ◽  
Arkadius Waleska
Keyword(s):  
Aqueous Solution ◽  
Cyclic Voltammetry ◽  
Coordination Chemistry ◽  
Aqueous Solutions ◽  
Iron Complexes ◽  
Redox Properties

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.

Electrochemical Reaction Mechanism of Tiron in Acidic Aqueous Solution

2011 ◽  
Vol 396-398 ◽  
pp. 1730-1735 ◽  
Author(s):  
Yan Xu ◽  
Yue Hua Wen ◽  
Jie Cheng ◽  
Gao Ping Cao ◽  
Yu Sheng Yang
Keyword(s):  
Aqueous Solution ◽  
Cyclic Voltammetry ◽  
Aqueous Solutions ◽  
Electrochemical Oxidation ◽  
Electrochemical Reaction ◽  
Mass Spectrometric ◽  
Acidic Aqueous Solution ◽  
Ece Mechanism ◽  
Flow Through ◽  
Electro Oxidation

Electrochemical oxidation of tiron in the presence of H2O as a nucleophile in strongly acidic aqueous solutions was studied by cyclic voltammetry, controlled-voltage coulometry and spectrometric investigations. The mechanism of electrochemical reaction is confirmed by spectrophotometric tracing in various times of controlled-voltage coulometry. The voltammetric and spectrophotometric foundations indicate that a 1,4-Michael addition of H2O from its hydroxy moiety to the position 4 of electrochemically derived o-quinone is occurred. The electrochemical oxidation and reduction of tiron has been successfully accomplished by controlled-voltage coulometry in a redox flow-through type cell and the final electro-reduced product was characterized by spectrophotometric, 1H NMR and mass spectrometric methods. It is demonstrated that the electro-oxidation of tiron follows an ECE mechanism in acidic aqueous solutions, leading to formation of a new compound of para- benzoquinone derivative.

scholarly journals Metal Complexes of Mixed Nucleobases. Part I: Synthesis and Characterization of Copper(II), Zinc(II), Cadmium(II) and Mercury(II) Complexes of Adenine and Uracil

2016 ◽  
Vol 64 (2) ◽  
pp. 127-133
Author(s):  
Humaira Yeasmin ◽  
MS Rahman ◽  
AA Shaikh ◽  
Pradip K Bakshi
Keyword(s):  
Aqueous Solution ◽  
Cyclic Voltammetry ◽  
Magnetic Susceptibility ◽  
Redox Properties ◽  
Synthesis And Characterization ◽  
Bidentate Ligands ◽  
Cadmium Complexes ◽  
X Ray ◽  
Metal Contents

The complexes of Cu(II), Zn(II), Cd(II) and Hg(II) with adenine (AdeH) and uracil (UraH) have been synthesized and characterized by a combination of metal contents estimation, IR, UV-vis spectral data, thermogravimetric analysis (QSTG, TG and DSC) and magnetic susceptibility measurement. All the complexes are micro-crystalline, slightly soluble in water and decompose at high temperature. Both adenine and uracil deprotonated under experimental condition and then ligated to the metal ions as bidentate ligands through N(3) and N(9) of adeninato (Ade), and through N(3) and C(2)=O of uracilato (Ura) anions. On the basis of the metal contents, the complexes are formulated as [M(C5H4N5O)(C5H4N5)(H2O)2] [M = Cu(II), Zn(II) and Hg(II)] and [Cd(C5H4N5)(C4H3N2O2)(H2O)2].2H2O. The redox properties of copper and cadmium complexes were examined in aqueous solution by cyclic voltammetry. The voltammograms show quasi-reversible behavior for both the complexes. The X-ray powder diffraction study of the copper complex indicates that it is poorly crystalline in nature. Dhaka Univ. J. Sci. 64(2): 127-133, 2016 (July)

Effect of thermal history of aqueous solutions of KCl on the metastable zone width

1984 ◽  
Vol 49 (3) ◽  
pp. 559-569 ◽  
Author(s):  
Jaroslav Nývlt
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Thermal History ◽  
Equilibrium Solubility ◽  
Metastable Zone Width ◽  
Zone Width ◽  
Preceding Experiment ◽  
History Of ◽  
Metastable Zone ◽  
The Given

The metastable zone width of an aqueous solution of KCI was measured as a function of the time and temperature of overheating above the equilibrium solubility temperature. It has been found that when the experiments follow close upon one another, the parameters of the preceding experiment affect the results of the experiment to follow.The results are interpreted in terms of hypotheses advanced in the literature to account for the effect of thermal history of solution. The plausibility and applicability of these hypotheses are assessed for the given cause of aqueous solution of a well soluble electrolyte.

scholarly journals I. Thermo-electric behaviour of aqueous solutions with mercurial electrodes

1879 ◽  
Vol 29 (196-199) ◽  
pp. 472-482 ◽  
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Internal Diameter ◽  
Thermo Electric ◽  
Thin Glass ◽  
Mercury Surface

In order to investigate this subject, I devised and constructed the following apparatus :—A and B are two thin glass basins, 81 millims. internal diameter (= 5,153 sq. millims. of mercury surface), and 6·0 centims. deep; each containing a layer of mercury about 1·0 centim. deep, covered by a layer, about 3 centims. deep, of the aqueous solution to be examined.

Redox Properties of CeIVDOTA in Carbonated Aqueous Solutions. A Radiolytic and an Electrochemical Study

2021 ◽  
Vol 125 (7) ◽  
pp. 1436-1446
Author(s):  
Inna Popivker ◽  
Dan Meyerstein ◽  
Dalia Gitin ◽  
Elad N. Avraham ◽  
Eric Maimon ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Redox Properties ◽  
Electrochemical Study

scholarly journals Meta-studtite stability in aqueous solutions. Impact of HCO3−, H2O2 and ionizing radiation on dissolution and speciation

2021 ◽  
Author(s):  
Junyi Li ◽  
Zoltán Szabó ◽  
Mats Jonsson
Keyword(s):  
Aqueous Solution ◽  
Ionizing Radiation ◽  
Aqueous Solutions ◽  
Carbonate Complexes ◽  
C Nmr

Four different uranyl-(peroxide)-carbonate complexes were identified during studtite and meta-studtite dissolution in aqueous solution containing 10 mM HCO3− by 13C NMR.

scholarly journals Visualization of microwave near-field distribution in sodium chloride and glucose aqueous solutions by a thermo-elastic optical indicator microscope

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhirayr Baghdasaryan ◽  
Arsen Babajanyan ◽  
Levon Odabashyan ◽  
Jung-Ha Lee ◽  
Barry Friedman ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Field Distribution ◽  
Near Field ◽  
Absorption Properties ◽  
Novel Approach ◽  
Concentration Changes ◽  
Biological Liquids ◽  
Optical Indicator ◽  
Distribution Intensity

AbstractIn this study, a new optical method is presented to determine the concentrations of NaCl and glucose aqueous solutions by using a thermo-elastic optical indicator microscope. By measuring the microwave near-field distribution intensity, concentration changes of NaCl and glucose aqueous solutions were detected in the 0–100 mg/ml range, when exposed to microwave irradiation at 12 GHz frequency. Microwave near-field distribution intensity decreased as the NaCl or glucose concentration increased due to the changes of the absorption properties of aqueous solution. This method provides a novel approach for monitoring NaCl and glucose in biological liquids by using a CCD sensor capable of visualizing NaCl and glucose concentrations without scanning.

Fabrication of monodisperse polypyrrole/SBA-15 composite for the selective removal of Cr(Ⅵ) from aqueous solutions

2021 ◽  
Author(s):  
Liang Wang ◽  
Peng Gao ◽  
Mengxin Liu ◽  
Ziqing Huang ◽  
Shixia Lan ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Adsorption Process ◽  
In Situ Polymerization ◽  
Selective Removal ◽  
Factors Affecting

Monodisperse polypyrrole/SBA-15 composite (PPy/SBA-15) was fabricated by in-situ polymerization and used for Cr(Ⅵ) adsorption from aqueous solution. PPy/SBA-15 was characterized by numerous approaches. Factors affecting the Cr(Ⅵ) adsorption process included...

Development of a method for detecting trace metals in aqueous solutions based on the coordination chemistry of hexahydrotriazines

The Analyst ◽  
2015 ◽  
Vol 140 (15) ◽  
pp. 5184-5189 ◽  
Author(s):  
Rudy J. Wojtecki ◽  
Alexander Y. Yuen ◽  
Thomas G. Zimmerman ◽  
Gavin O. Jones ◽  
Hans W. Horn ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Coordination Chemistry ◽  
Trace Metals ◽  
Aqueous Solutions ◽  
Detection System ◽  
Low Cost ◽  
System P ◽  
Chemical Indicator

The detection of trace amounts (<10 ppb) of heavy metals in aqueous solutions is described using hexahydrotriazines as a chemical indicator and a low cost fluorimeter-based detection system.

Integrity and redox properties of homogeneous and heterogeneous DNA films on gold surface probed by cyclic voltammetry

2002 ◽  
Vol 413 (1-2) ◽  
pp. 218-223 ◽  
Author(s):  
Hellas C.M Yau ◽  
Hing Leung Chan ◽  
Sen-fang Sui ◽  
Mengsu Yang
Keyword(s):  
Cyclic Voltammetry ◽  
Gold Surface ◽  
Redox Properties ◽  
Dna Films
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