Pressure effect on rate and equilibrium constants of reversible anionic .sigma.-complex formation between polynitroaromatics and lyate ions of water and methanol

1980 ◽  
Vol 102 (24) ◽  
pp. 7268-7272 ◽  
Author(s):  
Muneo Sasaki ◽  
Noboru Takisawa ◽  
Fujitsugu Amita ◽  
Jiro Osugi
Keyword(s):  
Complex Formation ◽  
Pressure Effect ◽  
Equilibrium Constants ◽  
Sigma Complex

Meisenheimer Complex Formation Between 1,3,5-Trinitrobenzene and Hydroxide Ion. Equilibrium Constants for the Dimethylformamide–Water Solvent System

1972 ◽  
Vol 50 (11) ◽  
pp. 1729-1733 ◽  
Author(s):  
E. A. Symons ◽  
E. Buncel
Keyword(s):  
Complex Formation ◽  
Aqueous Medium ◽  
Equilibrium Constant ◽  
Equilibrium Constants ◽  
Solvent System ◽  
Medium Composition ◽  
Hydroxide Ion ◽  
Spectrophotometric Methods ◽  
Water Solvent ◽  
Sigma Complex

Sigma-complex formation between 1,3,5-trinitrobenzene (TNB) and hydroxide ion has been studied quantitatively as a function of medium composition for part of the dimethylformamide (DMF)–water solvent system by spectrophotometric methods. Only a 1:1 complex is detected under the conditions of measurement, with [TNB] ≥ [OH−]. The equilibrium constant (Keq) for complex formation in 22 mol % DMF has the value 3 × 10−3 l mol−1, compared with 3 l mol−1 in purely aqueous medium. Further increases in Kcq occur as the DMF content of the medium is raised; in 50 mol % DMF Keq ≈ 105, but reliable Keq values could not be obtained in this region of medium composition. The increase in Keq with increasing DMF content is interpreted largely on the basis of hydroxide ion desolvation.

Ionic dissociation in complexes of iodine with triphenylarsine and triphenylstibine

1991 ◽  
Vol 69 (4) ◽  
pp. 606-610 ◽  
Author(s):  
Ying Ru Zhang ◽  
Ira Solomon ◽  
Seymour Aronson
Keyword(s):  
Complex Formation ◽  
Chemical Nature ◽  
Equilibrium Constants ◽  
Electrochemical Technique ◽  
High Iodine ◽  
Ionic Complex ◽  
Ionization Mechanisms ◽  
Iodine Complex ◽  
Ionic Dissociation ◽  
Iodine Complexes

An electrochemical technique has been employed to study the ionization of the iodine complexes of (C6H5)3As, (C6H5)3Sb, and pyridine. Several different ionization mechanisms are proposed depending on the chemical nature and concentration of the reactants. A new ionic complex, (C6H5)3MI22+ is postulated for the interaction of iodine with (C6H5)3As and (C6H5)3Sb at high iodine concentrations. Equilibrium constants have been calculated from the emf data for the various ionization steps. Key words: triphenylarsine, triphenylstibine, iodine, complex formation, ionization.

1-Iodoacétylènes. IV. Relations structure–réactivité pour la complexation des 1-iodoacétylènes substitués avec des bases de Lewis

1983 ◽  
Vol 61 (1) ◽  
pp. 135-138 ◽  
Author(s):  
Christian Laurence ◽  
Michèle Queignec-Cabanetos ◽  
Bruno Wojtkowiak
Keyword(s):  
Complex Formation ◽  
Triple Bond ◽  
Vibrational Frequency ◽  
Chemical Shifts ◽  
Structural Parameters ◽  
Equilibrium Constants ◽  
Lewis Acidity ◽  
Frequency Shifts ◽  
Substituent Constants ◽  
Substituted 1

The equilibrium constants for complex formation between the substituted 1-iodoacetylènes 1–8 and the vibrational frequency shifts induced by complex formation are related to the electronic substituent constants. The 13C chemical shifts of the triple bond are also useful structural parameters for predicting the Lewis acidity of iodoalkynes.

Studies of complex formation from permittivity measurements: a statistical reexamination

1992 ◽  
Vol 70 (7) ◽  
pp. 1873-1878 ◽  
Author(s):  
Otto Exner
Keyword(s):  
Dipole Moment ◽  
Complex Formation ◽  
Classical Method ◽  
Dipole Moments ◽  
Equilibrium Constants ◽  
Statistical Treatment ◽  
Statistical Procedure ◽  
Variable Ratio ◽  
Transformation Of Variables ◽  
Permittivity Measurements

Permittivity measurements on solutions of two compounds present in a variable ratio may reveal complex formation: both the equilibrium constant and the dipole moment of the complex can be in principle estimated. However, an incorrect statistical treatment involving transformation of variables is used quite often, for example, in the classical method of Few and Smith. In this case the estimates obtained are usually biased, or loaded with such a great uncertainty that they are practically worthless. The results of numerous papers, even some recent ones, are thus completely at variance with facts. This is shown in this paper by recalculating equilibrium constants and dipole moments of the complex in 17 examples from the literature. Simultaneously, a correct and simple statistical procedure is suggested. The danger of an incorrect and (or) incomplete statistical treatment may be encountered, for the same reason, even in other, quite different, areas.

Complex Formation in Ether–Chloroform Systems: Comparison of Thermodynamic and Spectroscopic Results

1974 ◽  
Vol 52 (11) ◽  
pp. 2139-2142 ◽  
Author(s):  
Neil F. Pasco ◽  
David V. Fenby ◽  
Loren G. Hepler
Keyword(s):  
Complex Formation ◽  
Equilibrium Constants ◽  
Liquid Vapor

A number of procedures for evaluation of equilibrium constants and standard enthalpies of complex formation from equilibrium liquid–vapor and calorimetric results have been applied to ether–chloroform systems. The results are compared with published spectroscopic values.

Kinetics and Equilibrium of Binding of Fe3+ by a Fulvic Acid: A Study by Stopped Flow Methods

1975 ◽  
Vol 53 (20) ◽  
pp. 2979-2984 ◽  
Author(s):  
Cooper H. Langford ◽  
Tahir R. Khan
Keyword(s):  
Ionic Strength ◽  
Complex Formation ◽  
Fulvic Acid ◽  
Metal Ion ◽  
Equilibrium Constants ◽  
Acid Dissociation ◽  
Stopped Flow ◽  
Solution Ph ◽  
Sulfosalicylic Acid ◽  
Flow Measurements

The first report of a rate of binding of a metal ion (Fe3+) by a soluble fulvic acid is derived from stopped flow measurements. The rate of complex formation is normal in Wilkins' sense and similar to that for sulfosalicylic acid. Dissociation is slow (t1/2 > 10 s). The binding of Fe3+ by the fulvic acid in acid solution, pH = 1–2.5, was investigated by kinetic analysis in which the reaction of free Fe3+ with sulfosalicylic acid was followed by stopped flow spectrophotometry on a time scale short compared to release of Fe3+ by fulvic acid. Conditional equilibrium constants found were 1.5 ± 0.3 × 104 at pH = 1.5 and 2.5, and 2.8 ± 0.3 × 103 at pH = 1.0 at 25 °C (ionic strength 0.1).

Factor analysis as a complement to band resolution. V. Complexing of pentachlorophenol and acetone in carbon tetrachloride solution

1978 ◽  
Vol 56 (23) ◽  
pp. 2959-2965 ◽  
Author(s):  
J. Korppi-Tommola ◽  
H. F. Shurvell
Keyword(s):  
Factor Analysis ◽  
Carbon Tetrachloride ◽  
Complex Formation ◽  
Infrared Spectrum ◽  
Equilibrium Constants ◽  
Complex Model ◽  
Carbon Tetrachloride Solution ◽  
Linear Relationships

Complex formation between pentachlorophenol and acetone and acetone-d6 in carbon tetrachloride solution has been studied in both the hydroxyl and carbonyl stretching regions of the infrared spectrum. Factor analysis of the digitized spectra indicates three absorbing components for each set of solutions in the hydroxyl stretching region. Concentration studies revealed roughly linear relationships between the areas of the 'free' ν(OH) band and both of the resolved complex bands, suggesting that two different 1:1 complexes occur in CCl4 solution. In the ν(CO) region only one band due to complex formation was detected. Equilibrium constants for the isotopically different complexes at about 30 °C are reported. In the hydroxyl stretching region, band resolution was also carried out using four components which gave a better fit to the observed spectrum. A set of equilibrium constants were then obtained. However, considerable difficulties were met in the calculations and in the interpretation of these results, so that the three band, two complex model is preferred.

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