scholarly journals Complications in complexation kinetics for lanthanides with DTPA using dye probe molecules in aqueous solution

RSC Advances ◽  
2017 ◽  
Vol 7 (42) ◽  
pp. 26507-26512 ◽  
Author(s):  
K. Larsson ◽  
T. D. Cullen ◽  
S. P. Mezyk ◽  
R. G. McDowell ◽  
L. R. Martin
Keyword(s):  
Aqueous Solution ◽  
Rate Constants ◽  
Probe Molecules ◽  
Ligand Displacement ◽  
Dye Probe ◽  
Complexation Kinetics

Dye probe molecules were used to investigate lanthanide complexation and verify the viability of the ligand displacement methodology for measuring DTPA complexation rate constants. Results showed that dye probes underestimate the rate constants.

Ferricyanide Oxidation of Butanol Homogeneously Catalysed by Chlororuthenium Complexes

1979 ◽  
Vol 32 (9) ◽  
pp. 1905 ◽  
Author(s):  
AF Godfrey ◽  
JK Beattie
Keyword(s):  
Aqueous Solution ◽  
Complex Formation ◽  
Linear Dependence ◽  
Rate Constants ◽  
Homogeneous Catalyst ◽  
Basic Solution ◽  
Rate Law ◽  
Kinetics Of ◽  
Solution Estimates ◽  
Butanol Concentration

The oxidation of butan-1-ol by ferricyanide ion in alkaline aqueous solution is catalysed by solutions of ruthenium trichloride hydrate. The kinetics of the reaction has been reinvestigated and the data are consistent with the rate law -d[FeIII]/dt = [Ru](2k1k2 [BuOH] [FeIII])/(2k1 [BuOH]+k2 [FeIII]) This rate law is interpreted by a mechanism involving oxidation of butanol by the catalyst (k1) followed by reoxidation of the catalyst by ferricyanide (k2). The non-linear dependence of the rate on the butanol concentration is ascribed to the rate-determining, butanol-independent reoxidation of the catalyst, rather than to the saturation of complex formation between butanol and the catalyst as previously claimed. Absolute values of the rate constants could not be determined, because some of the ruthenium precipitates from basic solution. With K3RuCl6 as the source of a homogeneous catalyst solution, estimates were obtained at 30�0�C of k1 = 191. mol-1 s-1 and k2 = 1�4 × 103 l. mol-1 s-1.

scholarly journals Kinetic and Thermodynamic Studies of Chromium (VI) Sorption by Pure and Carbonized Fluted Pumpkin waste biomass (Telfairia occidentalis Hook F.)

2012 ◽  
Vol 27 ◽  
pp. 11-18
Author(s):  
Timi Tarawou ◽  
Michael Horsfall
Keyword(s):  
Aqueous Solution ◽  
Rate Constants ◽  
Industrial Effluents ◽  
Second Order ◽  
Order Kinetic ◽  
Waste Biomass ◽  
Fluted Pumpkin ◽  
Chromium Vi ◽  
Telfairia Occidentalis ◽  
Pseudo Second Order

The adsorption of chromium (VI) ions from aqueous solution was studied using pure and carbonized fluted pumpkin waste biomass (FPWB). The kinetic data shows a pseudo-first-order mechanism with rate constants of 1.26 × 10-2 and 1.933 × 10-2 mg g-1 min-1 for the pure and carbonized FPWB, respectively. While the pseudo-second-order mechanism has rate constants of 0.93 × 10-1 and 1.33 × 10-1 mg g-1 min-1 for the pure and carbonized waste biomass respectively. The pseudo-second order kinetic model was found to be more suitable for describing the experimental data based on the correlation coefficient values (R2) of 0.9975 and 0.9994 obtained for pure waste biomass (PWB) and carbonized waste biomass (CWB), respectively. The results obtained from this study show that PWB and CWB have very high removal capacity for chromium (VI) from aqueous solution over a range of reaction conditions. Thus, fluted pumpkin waste biomass (Telfairia occidentalis Hook F) is a potential sorbent for the treatment of industrial effluents containing chromium (VI) contaminant.DOI: http://dx.doi.org/10.3126/jncs.v27i1.6436 J. Nepal Chem. Soc., Vol. 27, 2011 11-18Uploaded date: 16 July, 2012

An efficient and eco-friendly method for the thiol-Michael addition in aqueous solutions using amino acid ionic liquids (AAILs) as organocatalysts

2020 ◽  
Vol 92 (1) ◽  
pp. 97-106
Author(s):  
Roberto Figueroa Guíñez ◽  
José G. Santos ◽  
Ricardo A. Tapia ◽  
Jackson J. Alcazar ◽  
Margarita E. Aliaga ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Ionic Liquids ◽  
Amino Acid ◽  
Efficient Method ◽  
Michael Addition ◽  
Rate Constants ◽  
Michael Reaction ◽  
High Rate ◽  
Reusable Catalyst ◽  
Reaction Conditions

AbstractA series of amino-acid based ionic liquids (Bmim[AA]s) have been synthesized and evaluated as catalysts, in aqueous solution. The results of a kinetic study of the thiol-Michael reaction of L-Cysteine with trans-β-nitrostyrene demonstrated the advantages of using (Bmim[AA]s) as organocatalysts. The benefits include high rate constants; mild reaction conditions; and, a reusable catalyst, which leads to a simple and efficient method for these important kinds of reactions.

Studies of radiation-induced reactions of ethylene in aqueous solution II. Reactions in the presence of oxygen as studied by pulse radiolysis and γ -irradiation techniques

1967 ◽  
Vol 300 (1463) ◽  
pp. 443-454 ◽  
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Peroxide ◽  
Rate Constants ◽  
Pulse Radiolysis ◽  
Major Product ◽  
Peroxy Radicals ◽  
Ferrous Ions ◽  
Constant Composition ◽  
Γ Irradiation ◽  
Radiation Induced

The radiolysis of dilute aqueous solutions containing ethylene and oxygen has been investigated. Pulse radiolysis was used to measure the rate constants for the addition of hydroxyl radicals to ethylene, the binary decomposition of the resulting hydroxyethyl radicals and their addition to ethylene and reaction with oxygen to yield peroxy radicals. The rate constants have also been determined for the mutual interaction of the peroxy radicals and their reaction with ferrous ions. The principal products of γ -irradiation were aldehydes and organic hydroperoxides. Hydrogen peroxide was found in yields close to the molecular yield from water. The polymer produced in the absence of oxygen was not formed, and glycollaldehyde, reported as a major product by previous workers, could not be detected. At constant composition of the gas mixtures, product yields were unaffected by total pressure in the range up to 40 atm, but were strongly dependent on the proportion of oxygen. Aldehyde yields were markedly greater at pH 1.2 than in neutral solution. The influence of ferrous ions an d of added hydrogen peroxide has been determined. The pulse radiolysis and γ -irradiation experiments complement one another and show that the radiation-induced oxidation of ethylene in aqueous solution involves the same primary reactions as occur in the absence of oxygen, followed by the formation and further reactions of peroxy radicals.

Free-radical reductions of arenediazonium ions in aqueous solution. V. Pulse-radiolytic determination of rate constants for some para-substitutedbenzenediazonium ions

1981 ◽  
Vol 34 (7) ◽  
pp. 1433 ◽  
Author(s):  
JE Packer ◽  
J Monig ◽  
BC Dobson
Keyword(s):  
Aqueous Solution ◽  
Free Radical ◽  
Rate Constants ◽  
Substituent Effect ◽  
Reduction Potential ◽  
Radical Anions ◽  
Semiquinone Radical ◽  
Substituent Group

Some rate constants for the reduction of para-substituted benzenediazonium ions by the radicals eaq-, ·CH2OH, (CH3)2·COH and some semiquinone radical anions have been measured. The substituent group has no effect on the rates with eaq-, but as the reduction potential of the reducing radical becomes more positive, the substituent effect increases, electron-withdrawing groups enhancing the rates. No free halide is formed on reduction of p-BrC6H4N2+ or p-IC6H4N2+ by eaq- or ·CH2OH.

Reaction between alkali metal ferrocyanides and persulfates in aqueous solution

1967 ◽  
Vol 45 (20) ◽  
pp. 2411-2418 ◽  
Author(s):  
R. W. Chlebek ◽  
M. W. Lister
Keyword(s):  
Aqueous Solution ◽  
Alkali Metal ◽  
Rate Constants ◽  
Ion Pairs ◽  
Metal Cations ◽  
Activation Energies ◽  
Alkali Metal Cations ◽  
Potassium Salts ◽  
Apparent Activation Energies

The rates of the reaction of ferrocyanide and persulfate ions, in the presence of various concentrations of different alkali metal cations, have been measured at various temperatures and ionic strengths. The results are interpreted in terms of ion pairs and support the view that the actual reacting species are MFe(CN)6−3 and MS2O8−, where M is an alkali metal. This is similar to the situation found earlier for potassium salts of these ions. The rate constants obtained on this assumption increase gradually from lithium to cesium. Values are also obtained for the apparent activation energies of these reactions.

Sign in / Sign up

Export Citation Format

Share Document