Rate enhancement of the nickel(II)-pada complex formation in sodium alkanesulfonate micellar solutions

1982 ◽  
Vol 35 (1) ◽  
pp. 15 ◽  
Author(s):  
JR Hicks ◽  
VC Reinsborough
Keyword(s):  
Complex Formation ◽  
Chain Length ◽  
Micellar Solution ◽  
Binding Constants ◽  
Bidentate Ligand ◽  
Kinetic Constants ◽  
Micellar Solutions ◽  
Reaction Volume ◽  
Rate Of Reaction ◽  
Alkyl Sulfates

Sodium alkanesulfonates (C9, C8, C7, and C6) in micellar solution have been used to enhance the rate of reaction between Niaq2+ and the bidentate ligand pyridine-2-azo-p-dimethylaniline (pada) at 298.2 K. A Berezin-like model has been used to account for the observed kinetic constants in terms of the binding constants of each of the reagents to the micelles and the reaction volume and the concentration of the micellar surfactant. For a given chain length, the alkanesulfonates are about 25 % less effective than alkyl sulfates in promoting the rate of reaction and the model accounts for this successfully.

Effect of short-chained sodium alkylsulfate micelles on the kinetics of metal complex formation

1981 ◽  
Vol 59 (9) ◽  
pp. 1361-1367 ◽  
Author(s):  
Paul D. I. Fletcher ◽  
Vincent C. Reinsborough
Keyword(s):  
Alkyl Chain ◽  
Binding Constants ◽  
Micelle Formation ◽  
Reaction Rates ◽  
Bidentate Ligand ◽  
Alkyl Chain Length ◽  
Stopped Flow ◽  
Micellar Solutions ◽  
Kinetics Of ◽  
Micelle Surface

The kinetics of the reaction between Niaq2+ and the bidentate ligand pyridine-2-azo-p-dimethylaniline (PADA) have been investigated in micellar solutions of sodium decyl-, octyl-, and hexylsulfates using the stopped-flow technique. The rate of enhancement decreased with decreasing alkyl-chain length and from the Berezin or Robinson model could be quantitatively related to the independently measured binding constants of Ni2+ ion and PADA to the micelle surface. The dramatic effect of micelles upon the reaction rates in different directions of the Ni2+/PADA and the Ni2+/murexide reactions served as sensitive indicators of the cmc even at the very limit of micelle formation which relatively concentrated sodium hexylsulfate solutions represent.

Rate Enhancement of Nickel(II)-pada Complex-Formation in Mixed Sodium Perfluorooctanoate/Octanesulfonate Micellar Solutions

1990 ◽  
Vol 43 (1) ◽  
pp. 11 ◽  
Author(s):  
VC Reinsborough ◽  
TDM Stulz ◽  
XY Xiang
Keyword(s):  
Binding Constants ◽  
Kinetic Studies ◽  
Bidentate Ligand ◽  
Bulk Solution ◽  
Complexation Reaction ◽  
Reaction Volume ◽  
Rate Enhancement ◽  
Maximum Value ◽  
Sodium Perfluorooctanoate ◽  
Robinson Equation

Kinetic studies of the Niaq2+ ion complexation with the bidentate ligand pyridine-2-azo-p-dimethylaniline ( pada ) were conducted by the stopped-flow technique in the presence of mixed micelles of sodium perfluorooctanoate ( spfo ) and sodium octanesulfonate ( sos ). Binding constants for Niaq2+ and pada partitioning between bulk solution and micelles were determined through solubility measurements and the murexide techniques respectively. The molar reaction volume for the surfactant was obtained through the fitting of the kinetic data and partitioning constants to the Robinson equation. It was found that spfo micelles promoted the complexation reaction 400-fold just beyond the critical micelle concentration but this maximum value decreased with sos , NaCl or further spfo addition. The unexpected effectiveness of spfo in rate enhancement is due to its compact micellar reaction volume of 0.16 dm3 mol-1. The kinetic results are consistent with spfo and sos forming separate micelles of pure or almost pure composition.

scholarly journals Controllability of cupric particle synthesis by linear alcohol chain number as additive and pH control in cupric acetate solution using X-ray radiolysis

2019 ◽  
Vol 26 (6) ◽  
pp. 1986-1995 ◽  
Author(s):  
Akinobu Yamaguchi ◽  
Ikuo Okada ◽  
Ikuya Sakurai ◽  
Hirokazu Izumi ◽  
Mari Ishihara ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Chain Length ◽  
Cupric Oxide ◽  
Liquid Solution ◽  
Ph Control ◽  
Acetate Solution ◽  
Reaction Route ◽  
X Ray ◽  
Rate Of Reaction ◽  
Oxide Particles

Synthesis and immobilization of caltrop cupric particles onto a Si substrate using X-ray radiolysis directly from a liquid solution of Cu(COOCH3)2 is demonstrated. Caltrop cupric oxide particles are formed in the X-ray radiolysis of aqueous solutions of Cu(COOCH3)2, which also contain methanol, ethanol, 2-propanol or 1-propanol as ^\bulletOH scavenger. The blade lengths of the caltrop particles are dependent on the alcohol chain length. In particular, it was found that an alkyl alcohol whose chain length is longer than four is unable to synthesize any particles in aqueous solutions of Cu(COOCH3)2 in X-ray radiolysis. These results are attributed to the alkyl alcohol chain length influencing the rate of reaction of radicals and determines the solvable ratio of its alcohol into water. In addition, it was found that the synthesized particle geometric structure and composition can also be controlled by the pH of the aqueous solution in the X-ray radiolysis. This study may open a door to understanding and investigating a novel photochemical reaction route induced under X-ray irradiation. The development of the X-ray radiolysis process enables us to achieve the rapid and easy process of synthesis and immobilization of higher-order nano/microstructure consisting of various materials.

scholarly journals Oxidative Study of Benzaldehyde by Isoqauinolinium Bromo Chromate

2019 ◽  
Vol 16 ◽  
pp. 5354-5359
Author(s):  
Arun Kumar Dwivedi ◽  
K. N. Sharma ◽  
Arvind Prasad Dwivedi
Keyword(s):  
Dielectric Constant ◽  
Acetic Acid ◽  
Complex Formation ◽  
Benzoic Acid ◽  
Neutral Salt ◽  
Kinetics Analysis ◽  
Keto Form ◽  
Acetic Acid Medium ◽  
Oxidative Reaction ◽  
Rate Of Reaction

The kinetics analysis of the oxidative reaction between benzaldehyde and oxidant is quinolinium Bromo chromate was reported in aqueous 40% acetic acid medium at 313 K. The rate of reaction varies first-power of [IQBC] and [H2SO4], whereas fractional-order kinetics was observed for benzaldehyde. The rate constant gradually increases with decrease in dielectric constant of the medium. The neutral salt does not alter the rate. The metal cations (Cu++) slightly accelerate the rate of oxidation when added to reaction mixture. The study rules out the participation of keto form of substrate in complex formation. Benzoic acid was identified as the end-product in stoichiometrically 1:1 based mechanism. The rate law was derived in accordance with the kinetic results.

scholarly journals Calixarene-mediated assembly of a small antifungal protein

IUCrJ ◽  
2019 ◽  
Vol 6 (2) ◽  
pp. 238-247 ◽  
Author(s):  
Jimi M. Alex ◽  
Martin L. Rennie ◽  
Sylvain Engilberge ◽  
Gábor Lehoczki ◽  
Hajdu Dorottya ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Antifungal Activity ◽  
High Resolution ◽  
Complex Formation ◽  
Binding Site ◽  
Crystal Structures ◽  
Protein Assembly ◽  
Bidentate Ligand ◽  
Antifungal Protein ◽  
Protein Recognition

Synthetic macrocycles such as calixarenes and cucurbiturils are increasingly applied as mediators of protein assembly and crystallization. The macrocycle can facilitate assembly by providing a surface on which two or more proteins bind simultaneously. This work explores the capacity of the sulfonato-calix[n]arene (sclx n ) series to effect crystallization of PAF, a small, cationic antifungal protein. Co-crystallization with sclx4, sclx6 or sclx8 led to high-resolution crystal structures. In the absence of sclx n , diffraction-quality crystals of PAF were not obtained. Interestingly, all three sclx n were bound to a similar patch on PAF. The largest and most flexible variant, sclx8, yielded a dimer of PAF. Complex formation was evident in solution via NMR and ITC experiments, showing more pronounced effects with increasing macrocycle size. In agreement with the crystal structure, the ITC data suggested that sclx8 acts as a bidentate ligand. The contributions of calixarene size/conformation to protein recognition and assembly are discussed. Finally, it is suggested that the conserved binding site for anionic calixarenes implicates this region of PAF in membrane binding, which is a prerequisite for antifungal activity.

COMPLEX FORMATION BETWEEN BASIC ANTIBIOTICS AND DEOXYRIBONUCLEIC ACID IN HUMAN PULMONARY SECRETIONS

PEDIATRICS ◽  
1965 ◽  
Vol 36 (5) ◽  
pp. 714-720
Author(s):  
Joseph L. Potter ◽  
LeRoy W. Matthews ◽  
Samuel Spector ◽  
Joy Lemm
Keyword(s):  
Cystic Fibrosis ◽  
Sodium Chloride ◽  
Complex Formation ◽  
Chain Length ◽  
Deoxyribonucleic Acid ◽  
Antimicrobial Agents ◽  
Dnase I ◽  
Two Samples

1. Complex formation and precipitation of DNA by neomycin, with consequent inactivation of the antibiotic, has been shown to occur in the pulmonary secretions of patients with cystic fibrosis. 2. Highly polymerized DNA from a variety of sources, as well as two samples of RNA, were precipitated by neomycin in vitro. Polymixin, kanamycin, colymycin, and streptomycin similarly co-precipitate with DNA in vitro. 3. The minimum chain length of polynucleotide required for precipitation in the DNA-neomycin system was 10. 4. The complex is readily attacked by DNase I resulting in the splitting of the DNA and the liberation of the antibiotic. Both components of the complex are solubilized in M sodium chloride. 5. The resistance of purulent foci of infection to therapy with basic antimicrobial agents may, in part, be due to the complex formation with the high levels of DNA found at the site of infection.

Kinetic and spectrophotometric studies of binding of iron(III) by glutathione

1976 ◽  
Vol 54 (20) ◽  
pp. 3192-3199 ◽  
Author(s):  
Tahir R. Khan ◽  
Cooper H. Langford
Keyword(s):  
Complex Formation ◽  
Kinetic Method ◽  
Binding Constants ◽  
Chelating Agent ◽  
Formation Reaction ◽  
Spectrophotometric Data ◽  
Natural Water Chemistry ◽  
Kinetics Of ◽  
Sulfur Containing

In this report, determination of unbound aquo iron species is accomplished by a kinetic method involving reaction with sulfosalicylic acid (SSA) on a time scale which is very short with respect to reaction of SSA with the glutathione complexes of iron. The data are used to calculate conditional binding constants for Fe(III) to glutathione. Binding constants in 0.1 M ionic strength media were obtained between pH 1 and 2.4 by the kinetic method, and near pH = 3 by spectrophotometry and by examination of the ratio of rate of complex formation and dissociation. The conditional binding 'constant' between pH 1 and 3 is represented as pK = −1.96 – 0.50pH. This is consistent with the importance of reactions involving only very limited proton release. Spectrophotometric data show that the —OH group on Fe(OH)2+ is lost on glutathione complexing. Kinetics of the complex formation reaction between aquo iron(III) species and glutathione are slower than rates of reaction of iron(III) with simple ligands.The glutathione system is regarded as a model system important to natural water chemistry because it is a widely distributed biological sulfur-containing chelating agent.

Effect of chain scission on flow characteristics of wormlike micellar solutions past a confined microfluidic cylinder: a numerical analysis

Soft Matter ◽  
2020 ◽  
Vol 16 (22) ◽  
pp. 5261-5272 ◽  
Author(s):  
Mohd Bilal Khan ◽  
C. Sasmal
Keyword(s):  
Numerical Analysis ◽  
Elastic Wave ◽  
Micellar Solution ◽  
Flow Characteristics ◽  
Chain Scission ◽  
Critical Value ◽  
Weissenberg Number ◽  
Elastic Instability ◽  
Micellar Solutions ◽  
Wave Phenomena

Elastic instability and elastic wave phenomena can be seen for the flow of a wormlike micellar solution past a confined microfluidic cylinder once the Weissenberg number exceeds a critical value.

Sign in / Sign up

Export Citation Format

Share Document