Metallomicellar Hydrolytic Catalysts Containing Ligand Surfactants Derived from Alkyl Pyridin-2-yl Ketoxime

1997 ◽  
Vol 62 (8) ◽  
pp. 1342-1354 ◽  
Author(s):  
Radek Cibulka ◽  
David Dvořák ◽  
František Hampl ◽  
František Liška
Keyword(s):  
Metal Ion ◽  
Transition Metal Ions ◽  
Water Soluble ◽  
Hexadecyltrimethylammonium Bromide ◽  
Pseudo First Order Reaction ◽  
Reaction Conditions ◽  
Catalytic Systems ◽  
First Order ◽  
Substrate Cleavage ◽  
Kinetics Of

N-Hexyl- (2a), N-octyl- (2b), N-decyl- (2c) and N-dodecyl-N-[2-(hydroxyimino)-2-(pyridin-2-yl)ethyl]dimethylammonium (2d) nitrates were synthesized as water-soluble cationic ligand surfactants. Three types of micellar catalytic systems employing salts 2 were prepared: homomicellar water solutions of salts 2, comicellar solutions of salts 2 with an inert cationic tenside hexadecyltrimethylammonium bromide (CTAB) and comicellar systems consisting of complexes of ligand surfactants 2 with transition metal ions (Co(II), Ni(II), Cu(II) and Zn(II)) and CTAB. Hydrolytic efficiency of all micellar and metallomicellar systems was tested by measuring the kinetics of the model substrate cleavage under pseudo-first-order reaction conditions. Of the above-mentioned catalysts, comicellar systems of salts 2 comicellized with CTAB were most efficient. In all cases, with the exception of Zn(II), coordination of a metal ion decreased the hydrolytic efficiency of salts 2.

Kinetics of metribuzin degradation by colloidal manganese dioxide in absence and presence of surfactants

2014 ◽  
Vol 68 (1) ◽  
Author(s):  
Qamruzzaman ◽  
Abu Nasar
Keyword(s):  
Sodium Dodecyl ◽  
Oxidative Degradation ◽  
Activation Parameters ◽  
Water Soluble ◽  
Ionic Surfactant ◽  
Ammonium Bromide ◽  
Pseudo First Order Reaction ◽  
First Order ◽  
Colloidal Mno2 ◽  
Kinetics Of

AbstractThe kinetics of the degradation of metribuzin by water-soluble colloidal MnO2 in acidic medium (HClO4) were studied spectrophotometrically in the absence and presence of surfactants. The experiments were performed under pseudo-first-order reaction conditions in respect of MnO2. The degradation was observed to be of the first order in respect of MnO2 while of fractional order for both metribuzin and HClO4. The rate constant for the degradation of metribuzin was observed to decrease as the concentration of MnO2 increased. The anionic surfactant, sodium dodecyl sulphate (SDS), was observed to be ineffective whereas the non-ionic surfactant, Triton X-100 (TX-100), accelerated the reaction rate. However, the cationic surfactant, cetyltrimethyl ammonium bromide (CTAB), caused flocculation with oppositely-charged colloidal MnO2; hence further study was not possible. The catalytic effect of TX-100 was discussed in the light of the available mathematical model. The kinetic data were exploited to generate the various activation parameters for the oxidative degradation of metribuzin by colloidal MnO2 in the absence as well as the presence of the non-ionic surfactant, TX-100.

scholarly journals Kinetics and mechanism of sol-gel transformation between some trivalent- and tetravalent-metal ions and Sodium alginate Anionic polyelectrolyte with formation of coordination Biopolymeric structure polymembranes Hydrogels of Capillary Structures Ex

2007 ◽  
Vol 3 (1) ◽  
pp. 133-142 ◽  
Author(s):  
Ishaq Abdullah Zaafarany
Keyword(s):  
Sodium Alginate ◽  
Metal Ion ◽  
Sol Gel ◽  
Coordination Geometry ◽  
Large Excess ◽  
First Order ◽  
Pseudo First Order ◽  
The Stability ◽  
Kinetics Of ◽  
Overall Kinetics

Abstract          The kinetics of sol-gel transformation between A13+, La 3+ and Th4+ metal ion electrolytes and sodium alginate sol have been studied complexometrically at various  temperatures. In the presence of a large excess of sodium alginate sol concentration over that of metal ion electrolyte, the pseudo first–order plots of exchange showed sigmoidal curves with two distinct stages. The initial part was relatively fast and curved significantly at early times, followed by a slow decrease in the rates of exchange over longer time periods. The rate constants of gelation showed second-order overall kinetics which was first order in the concentration of both reactants. The thermodynamic parameters have been evaluated and tentative gelation mechanisms consistent with the kinetic results of gelation are suggested. The stability of these ionotropic metal-alginate complexes has been discussed in terms of the coordination geometry and strength of chelated bonds.

scholarly journals Cyclopentadienone Iron Tricarbonyl Complexes-Catalyzed Hydrogen Transfer in Water

Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 421 ◽  
Author(s):  
Daouda Ndiaye ◽  
Sébastien Coufourier ◽  
Mbaye Diagne Mbaye ◽  
Sylvain Gaillard ◽  
Jean-Luc Renaud
Keyword(s):  
Metal Complexes ◽  
Hydrogen Transfer ◽  
Low Cost ◽  
Pure Water ◽  
Free Water ◽  
Water Soluble ◽  
Tricarbonyl Complex ◽  
Reaction Conditions ◽  
Catalytic Systems ◽  
Iron Tricarbonyl

The development of efficient and low-cost catalytic systems is important for the replacement of robust noble metal complexes. The synthesis and application of a stable, phosphine-free, water-soluble cyclopentadienone iron tricarbonyl complex in the reduction of polarized double bonds in pure water is reported. In the presence of cationic bifunctional iron complexes, a variety of alcohols and amines were prepared in good yields under mild reaction conditions.

FIBRINOPEPTIDE B RELEASE FROM NORMAL FIBRINOGEN AND FIBRINOGEN LONDON I IN THE PRESENCE OF INHIBITORS OF FIBRIN POLYMERIZATION

1987 ◽  
Author(s):  
W Ruf ◽  
A Bender ◽  
K T Preissner ◽  
D A Lane ◽  
G Müller-Berghaus
Keyword(s):  
Initial Phase ◽  
Slow Rate ◽  
Order Reaction ◽  
Pseudo First Order Reaction ◽  
Reaction Conditions ◽  
Fibrin Polymerization ◽  
First Order ◽  
Molar Excess ◽  
Pseudo First Order ◽  
Fibrinogen Molecule

The fibrinopeptides A and B (FPA and FPB) are cleaved from the fibrinogen molecule with different rates. In the initial phase of the thrombin-fibrinogen reaction, FPB is released with a slow rate, which is enhanced upon polymerization of desA-fi-brin monomers. The aim of the present study was to further characterize the mechanism leading to the enhanced rate of FPB release during polymerization. For this purpose, the release of FPB from normal fibrinogen and from fibrinogen London I, which exhibits a polymerization defect located in the D-domain, was studied in the presence and absence of the fibrinolytic fragment D1 (D1) and of the synthetic tetrapeptide Gly-Pro-Arg-Pro (GPRP). Steady state parameters for fibrinopeptide release were determined under pseudo-first order reaction conditions. In the initial phase of the thrombin-fibrinogen reaction, the release of FPA was unchanged in the presence of D1. Furthermore, the release of FPA from fibrinogen London I did not reveal any difference in comparison to normal fibrinogen. GPRP prevented not only fibrin polymerization, but also the enhanced rate of FPB release. On the contrary, the rate of FPB release in the presence of a 16- and 32-fold molar excess of over fibrinogen did not differ from a reaction mixture with no added D1. Si-miliar to the inhibited rate of FPB release in the presence of GPRP, the release of FPB from fibrinogen London I occurred with a slow rate, which was not enhanced by the addition of a 16-fold molar excess of D1. Since the release neither from normal fibrinogen nor from ribrinogen London I was affected by D1, it was concluded that the D-E contact formed by D1 with an E-domain of a desA-fibrin molecule does not enhance the release of FPB. While GPRP keeps fibrin in monomeric form by inhibiting the polymerization sites in the D-domains, D1 does not prevent the formation of fibrin oligomers. Therefore, acceleration of FPB release is caused by a conformational change, which is induced by binding of reciprocal polymerization sites to an E-as well as a D-domain of the same desA-fibrin molecule.

Kinetics of Cs adsorption/desorption on granite by a pseudo first order reaction model

2007 ◽  
Vol 275 (3) ◽  
pp. 555-562 ◽  
Author(s):  
Shih-Chin Tsai ◽  
Tsing-Hai Wang ◽  
Yuan-Yaw Wei ◽  
Wen-Chun Yeh ◽  
Yi-Lin Jan ◽  
...  
Keyword(s):  
Reaction Model ◽  
Order Reaction ◽  
First Order Reaction ◽  
Pseudo First Order Reaction ◽  
First Order ◽  
Pseudo First Order ◽  
Adsorption Desorption ◽  
Kinetics Of

Quaternary Heteroarenium Aldoximes as Catalysts for Cleavage of Phosphate Esters

1995 ◽  
Vol 60 (5) ◽  
pp. 883-893 ◽  
Author(s):  
František Hampl ◽  
Jiří Mazáč ◽  
František Liška ◽  
Jiří Šrogl ◽  
Lubomír Kábrt ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Critical Micellar Concentration ◽  
Considerable Effect ◽  
Phosphate Esters ◽  
Hexadecyltrimethylammonium Bromide ◽  
Hydrolytic Cleavage ◽  
Pseudo First Order Reaction ◽  
First Order ◽  
Diphenyl Phosphate ◽  
Hydrolysis Of

1-Methyl- (Ia - Id) and 1-dodecyl-2-, 3- and 4-hydroxyiminomethylpyridinium salts (Ie - Ih), as well as 1-methyl- (IIa) and 1-dodecyl-3-hydroxyiminomethylpyridazinium salts (IIb, IIc), were synthesized as catalysts for hydrolytic cleavage of organophosphates. The activities of the prepared catalysts were evaluated by measuring rate constants of hydrolysis of 4-nitrophenyl diphenyl phosphate (PNPDPP) under conditions of a pseudo-first-order reaction. The observed reactivity of pyridinium aldoximes Ia - Ih towards PNPDPP in neutral or slightly basic aqueous solutions (pH 7.2 and 7.8) depends on the acidity of the hydroxyimino group. The cleavage of PNPDPP is strongly accelerated in solutions of 1-dodecylhydroxyiminomethylpyridinium salts Ie - Ih above their critical micellar concentration (CMC). Considerable effect on the velocity of PNPDPP cleavage was observed when quaternary pyridinium aldoximes Ie - Ih were comicellized with inert cationic tenside hexadecyltrimethylammonium bromide (CTAB). 1-Dodecyl-3-hydroxyiminomethylpyridazinium salts IIb and IIc were unstable in aqueous solutions under the above-mentioned conditions.

scholarly journals Synthesis of New Five Coordinated Copper(II) and Nickel(II) Complexes of L-Valine and Kinetic Study of Copper(II) with Calf Thymus DNA

2002 ◽  
Vol 9 (1-2) ◽  
pp. 81-90 ◽  
Author(s):  
Aijaz Ahmad Tak ◽  
Farukh Arjmand ◽  
Sartaj Tabassum
Keyword(s):  
Metal Ion ◽  
Binding Mode ◽  
Molar Conductance ◽  
Order Conditions ◽  
Calf Thymus Dna ◽  
First Order ◽  
Reversible Redox ◽  
Calf Thymus ◽  
Vis Spectroscopy ◽  
Kinetics Of

Five coordinated novel complexes of CuII and NiII have been synthesized from benzil and 1,3- diaminopropane-CuII/NiII complex and characterized by elemental analysis, i.r., n.m.r., e.p.r, molar conductance and u.v-vis, spectroscopy. The complexes are ionic in nature and exhibit pentaeoordinated geometry around the metal ion. The reaction kinetics of C25H36N5O2CuCl with calf thymus DNA was studied by u.v-vis, spectroscopy in aqueous medium. The complex after interaction with calf thymus DNA shows shift in the absorption spectrum and hypochromicity indicating an intercalative binding mode. The Kobs values have been calculated under pseudo-first order conditions. The redox behaviour of complex C25H36N5O2CuCl in the presence and in the absence of calf thymus DNA in the aqueous solution has been investigated by cyclic voltammetry. The cyclic voitammogram exhibits one quasi-reversible redox wave corresponding to CuII/CuI redox couple with E1/2 values of -0.377 and -0.237 V respectively at a scan rate of 0.1Vs-1 .On interaction with calf thymus DNA, the complex C25H36N5O2CuCl exhibits shifts in both Ep as well as in E1/2 values, indicating strong binding of the complex to the calf thymus DNA.

Equilibrium and Kinetics of Reactive Extraction of Propionic Acid Using Aliquat 336 and Tri-n-Butyl Phosphate in n-Hexanol

2009 ◽  
Vol 7 (1) ◽  
Author(s):  
Dr. Kailas L. Wasewar ◽  
Amit Keshav ◽  
Shri Chand
Keyword(s):  
Propionic Acid ◽  
Acid Concentration ◽  
Fermentation Broth ◽  
Reactive Extraction ◽  
Acid Extraction ◽  
Aliquat 336 ◽  
Pseudo First Order Reaction ◽  
First Order ◽  
Pharmaceutical Industries ◽  
Kinetics Of

Recovery of propionic acid from different sources, like aqueous streams or from fermentation broth, is important in view of its wide usage in food, chemical and pharmaceutical industries. Reactive extraction is an emerging separation technique having numerous advantages like high selectivity and recovery. Effect of acid concentration, extractant concentration, pH, temperature and kinetics are the important steps in the reactive extraction. Equilibrium of propionic acid extraction using tri-n-butyl phosphate (TBP) and Aliquat 336 in n-hexanol respectively was carried out to find the better extractant out of the two for extraction of propionic acid. Aliquat 336 was found to be better than TBP with Ks = 2.2119 m3/kmol, thus indicating good complexation between it and the acid. The kinetics of extraction of the acid using Aliquat 336 in a stirred cell was investigated. The reaction was found to be first order in acid concentration and zero order in Aliquat 336 concentration. The reaction was found to be fast pseudo first order reaction occurring in the diffusion film and was found to be independent of hydrodynamics conditions. Rate constant was evaluated to be 163.398 1/s.

scholarly journals Kinetics of Transition Metal Ion Catalyzed Oxidation of some Industrially Important Alcohols using Ammonium Meta Vanadate in Acidic Medium

2020 ◽  
pp. 35-41
Author(s):  
Harichandra A Parbat ◽  
D V Prabhu ◽  
Anna Pratima Nikalje
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Acidic Medium ◽  
Metal Ion ◽  
Crop Protection ◽  
Transition Metal Ions ◽  
Primary Alcohols ◽  
Oxidation Of Alcohols ◽  
Ammonium Meta Vanadate ◽  
Kinetics Of

Oxidation of alcohols has industrial importance as it yields several useful products.Toxic and costly metal ions like Os(VIII), Cr(VI), and Ru in different oxidation states are widely used for the oxidation of a variety of organic compounds. We are reporting herein the oxidation of the industrially useful primary alcohols, 2-Chloroethanol, 2-Butoxyethanol and 2-Phenoxyethanol using Ammonium metavanadate in acidic medium. Relatively less toxic and cheaper transition metal ions of the first series are effectively used as homogeneous catalysts for the oxidation of the alcohols to the corresponding aldehydes. 2- Chloroethanol is used as a precursor for ethylene oxide and is useful in the manufacture of crop protection chemicals, and pharmaceuticals.2-Butoxyethanol finds use in the making of paints, varnishes and industrial and household cleaners.

Oxidative Degradation and Kinetics of Trichloroethylene by Thermally Activated Persulfate

2014 ◽  
Vol 675-677 ◽  
pp. 547-550
Author(s):  
Jun Jie Yue ◽  
Xiao Qiao Zhu ◽  
Yu Ting Wang ◽  
Yu Qin Zhang ◽  
Li Zhao ◽  
...  
Keyword(s):  
Oxidative Degradation ◽  
Chemical Oxidation ◽  
Molar Ratio ◽  
Pseudo First Order Reaction ◽  
In Situ Chemical Oxidation ◽  
First Order ◽  
Molar Ratios ◽  
Thermally Activated ◽  
Kinetics Of

In situ chemical oxidation with persulfate (PS) anion (S2O82-) is a viable technique for remediation of groundwater contaminants such as trichloroethylene (TCE). This laboratory study investigated the use of the oxidant sodium PS for the chemical oxidation of TCE at different conditions to determine the influence of temperature, pH, and the PS/TCE molar ratio. Experiments revealed that higher temperatures, lower pH, and higher PS/TCE molar ratios were to the benefit of TCE oxidation by PS. By investigating the reaction kinetics, the degradations of contaminant can be described by use of pseudo-first-order reaction. At the temperatures ranging from 25°C to 40°C, the activation energy for the degradation of TCE was determined to be 85.04 KJ/mol.

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