Dissociation of substituted benzenesulphonamides in water, methanol and ethanol

1984 ◽  
Vol 49 (5) ◽  
pp. 1182-1192 ◽  
Author(s):  
Miroslav Ludwig ◽  
Oldřich Pytela ◽  
Karel Kalfus ◽  
Miroslav Večeřa
Keyword(s):  
Linear Regression ◽  
Multiple Linear Regression ◽  
Potentiometric Titration ◽  
Principal Components ◽  
Dissociation Constants ◽  
Benzoic Acids ◽  
Reaction Constant ◽  
The Media ◽  
Reaction Constants

Thirteen monosubstituted arylsulphonamides (XC6H4SO2NH2) and two 3,4-disubstituted arylsulphonamides (X2C6H3SO2NH2) have been synthetized and their dissociation constants have been measured by potentiometric titration in water, methanol, and ethanol. The Hammett substitution dependences have been calculated for all the media, and changes in the reaction constants due to transition from water to alcohols are discussed in confrontation with analogous dependences of benzoic acids. The reaction constant ρ found in methanol is lower than that in water. The dissociation constants have been treated mathematically by the method of the principal components and by multiple linear regression.

Dissociation constants of substituted benzoic acids in water and in organic solvents

1986 ◽  
Vol 51 (10) ◽  
pp. 2135-2142 ◽  
Author(s):  
Miroslav Ludwig ◽  
Václav Baron ◽  
Karel Kalfus ◽  
Oldřich Pytela ◽  
Miroslav Večeřa
Keyword(s):  
Potentiometric Titration ◽  
Organic Solvents ◽  
Solvent Effects ◽  
Dissociation Constants ◽  
Point Of View ◽  
Benzoic Acids ◽  
Hammett Equation ◽  
Substituent Constant ◽  
Reaction Constant ◽  
Substituted Benzoic Acids

Potentiometric titration has been used to measure dissociation constants of 38 monosubstituted benzoic acids in water and in 6 organic solvents (methanol, ethanol, dimethylformamide, acetonitrile, sulfolane, acetone). The results have been analyzed and interpreted from the point of view of substituent and solvent effects on the dissociation of the title substrates. It has been proved that solvents affect not only the reaction constant but also the substituent constant of the Hammett equation.

Solvent Effect on the Hammett Reaction Constant of Substituted Benzoic Acids

1993 ◽  
Vol 46 (1) ◽  
pp. 31 ◽  
Author(s):  
H Bartnicka ◽  
I Bojanowska ◽  
MK Kalinowski
Keyword(s):  
Solvent Effect ◽  
Dimethyl Sulfoxide ◽  
Dissociation Constants ◽  
Benzoic Acids ◽  
Hammett Equation ◽  
P Values ◽  
Reaction Constant ◽  
Substituted Benzoic Acids ◽  
Reaction Constants ◽  
Solvent Acidity

Potentiometric titration has been used to measure dissociation constants of 13 monosubstituted benzoic acids in nitromethane, benzonitrile , acetonitrile , propylene carbonate, acetone, N,N-dimethylformamide, dimethyl sulfoxide, methanol and formamide. The reaction constants of the Hammett equation were found to depend on the solvent acidity and basicity expressed by the α and β parameters of Kamlet and Taft. The p values determined earlier in water and ethanol also obey this rule.

scholarly journals Relationship between the Physical Properties and Hand of Jean Fabric

2016 ◽  
Vol 16 (3) ◽  
pp. 138-145 ◽  
Author(s):  
Atsushi Kawamura ◽  
Chunhong Zhu ◽  
Julie Peiffer ◽  
KyoungOk Kim ◽  
Yi Li ◽  
...  
Keyword(s):  
Principal Component Analysis ◽  
Linear Regression ◽  
Physical Properties ◽  
Multiple Linear Regression ◽  
Principal Components ◽  
Evaluation System ◽  
Principal Component ◽  
Semantic Differential ◽  
Differential Method ◽  
Fabric Hand

Abstract We investigated the distinctive characteristics of jean fabrics (denim fabrics obtained from jeans) and compared the physical properties and the hand. We used 13 kinds of jean fabric from commercial jeans and 26 other fabric types. The physical properties were measured using the Kawabata evaluation system, and the fabric hand was evaluated by 20 subjects using a semantic differential method. To characterise the hand of jean fabrics compared with other fabrics, we used principal component analysis and obtained three principal components. We found that jean fabrics were characterised by the second principal component, which was affected by feelings of thickness and weight. We further characterised the jean fabrics according to ‘softness & smoothness’ and ‘non-fullness’, depending on country of origin and type of manufacturer. The three principal components were analysed using multiple linear regression to characterise the components according to the physical properties. We explained the hand of fabrics including jean fabrics using its association with physical properties.

The Hammett substituent constants and effects of medium

1986 ◽  
Vol 51 (10) ◽  
pp. 2143-2150 ◽  
Author(s):  
Oldřich Pytela ◽  
Miroslav Ludwig ◽  
Miroslav Večeřa
Keyword(s):  
Factor Analysis ◽  
Principal Components Analysis ◽  
Excellent Agreement ◽  
Principal Components ◽  
Solvent Effects ◽  
Dissociation Constants ◽  
Benzoic Acids ◽  
Substituent Constants ◽  
Components Analysis ◽  
Substituted Benzoic Acids

The dissociation constants measured earlier for 35 substituted benzoic acids in seven solvents (water, methanol, ethanol, dimethylformamide, acetonitrile, sulfolane, and acetone) have been submitted to the principal components analysis and the factor analysis to produce sets of the Hammett substituent constants. The solvent effects have been evaluated on the dissociation constants of the substituted benzoic acids and, hence, also on the respective substituent constants. He differences have been compared between the substituent constants determined by the principal components analysis and by the factor analysis, the latter being found to be more suitable. The obtained sets of substituent constants have been confronted with literature data, and an excellent agreement has been found between the σ constants derived from the measurements in water with the sets of primary substituent constants and some other sets.

Chemometrical Analysis of Substituent Effects. IV. Additivity of Substituent Effects in Dissociation of 3,5-Disubstituted Benzoic Acids in Organic Solvents

1994 ◽  
Vol 59 (7) ◽  
pp. 1637-1644 ◽  
Author(s):  
Oldřich Pytela ◽  
Jiří Kulhánek ◽  
Miroslav Ludwig
Keyword(s):  
Organic Solvents ◽  
Dissociation Constants ◽  
Quantitative Description ◽  
Substituent Effects ◽  
Benzoic Acids ◽  
Hammett Equation ◽  
Specific Solvation ◽  
Reaction Constant ◽  
Substituent Constants ◽  
The Individual

Ten 3,5-disubstituted benzoic acids have been synthesized containing all possible combinations of the following substituents: CH3O, CH3, Cl/Br, NO2. The dissociation constants of these acids have been measured in seven organic solvents (methanol, acetone, dimethyl sulfoxide, dimethylformamide, acetonitrile, pyridine, 1,2-dichloroethane). It has been found that the effect of disubstitution is smaller than that due to interaction of substituents or their solvation and represents only about 0.2% of the effect caused by the individual substituents. The additivity in 3,5-disubstitution is about 2 - 3 times as good as that in 3,4-disubstitution. The quantitative description of substituent effects at the 3 and 5 positions is additive within the range of validity of the Hammett equation irrespective of the type of the substituent constants adopted, the addition of the multiplicative term being statistically insignificant. The solvent effect on 3,4- and 3,5-disubstituted derivatives is somewhat different at the same value of the reaction constant, due predominantly to the specific solvation of the 4-CH3O and 4-NO2 groups.

Chemometrical Analysis of Substituent Effects. III. Additivity of Substituent Effects in Dissociation of 3,4-Disubstituted Benzoic Acids in Organic Solvents

1994 ◽  
Vol 59 (3) ◽  
pp. 627-638 ◽  
Author(s):  
Oldřich Pytela ◽  
Jiří Kulhánek ◽  
Miroslav Ludwig ◽  
Václav Říha
Keyword(s):  
Dimethyl Sulfoxide ◽  
Organic Solvents ◽  
Dissociation Constants ◽  
Substituent Effects ◽  
Proton Donor ◽  
Benzoic Acids ◽  
Correlation Equations ◽  
Hammett Equation ◽  
Validity Range ◽  
Reaction Constants

Sixteen 3,4-disubstituted benzoic acids (with all combinations of CH3O, CH3, Cl/Br, and NO2 substituents) have been synthesized and their dissociation constants measured in seven organic solvents (methanol, acetone, dimethyl sulfoxide, dimethylformamide, acetonitrile, pyridine, 1,2-dichloroethane). The effect of disubstitution and the validity of additive correlation relationships based on the Hammett equation have been analyzed by means of the analysis of variance, comparison of overall residual standard deviations of correlation equations of additive and additive multiplicative type, and application of the Hammett equation with internal (latent, defined in various ways) parameters and external (taken from literature) parameters describing the substituent effects. The effect of disubstitution has been found to be additive and describable within the validity range of the substituent constants adopted - by applying the additivity principle without any additional correction for interactions between the two substituents. The same conclusion has been drawn from the comparison of overall residual deviations in correlation equations for mono- and disubstituted derivatives. The analysis of differences between the reaction constants of the Hammett equation applied to mono- and disubstituted benzoic acids has shown that in organic solvents the solvation of substituents makes various contributions. The substituent influence is stronger in polar aprotic solvents (acetone, dimethyl sulfoxide, dimethylformamide, acetonitrile) than that in the protic, basic, and less polar ones in which the stabilization by hydrogen bond becomes important, the role of proton donor being played either by the solvent itself (methanol) or by its conjugated acid (pyridine) or by a molecule of the dissociating acid as a consequence of homoconjugation (1,2-dichloroethane).

scholarly journals DETERMINANTS OF INTEREST IN SAVING FOR STUDENTS IN ISLAMIC BANKING

2020 ◽  
Vol 4 (2) ◽  
pp. 89-100
Author(s):  
Wahyuning Murniati ◽  
Deni Juliasari ◽  
Nani Hanifah
Keyword(s):  
Linear Regression ◽  
Multiple Linear Regression ◽  
Coefficient Of Determination ◽  
Islamic Banking ◽  
Student Interest ◽  
Independent Variables ◽  
Analysis Technique ◽  
The Media ◽  
Islamic Economic

Saving money is the way to regulate our finance effectively. Bank is one of the media that is considered quite effective for this activity. The development of Islamic economic make sharia banking practices increase in an innovative way. Various sharia bank products have become a choice for saving activity. The same thing happen for student. Although the interest to save is still lacking, but the use of sharia bank products is quite beneficial for their future. The purpose of this study is to analyze the factors that influence student interest in saving on Islamic banking. Multiple linear regression is an analysis technique with hypothesis testing to support its conclusions. With a coefficient of determination of 61.2%, the results of the analysis show the level of student education of the sharia economy has a significant effect compared to other variables on students' interest in saving. But simultaneously, all independent variables influence the interest in saving students in Islamic banking. This shows that education is very important for students, therefore STIE Widya Gama Lumajang should indeed provide quality teaching to students, especially in the field of Islamic economics

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