scholarly journals The study of linear solvation energy relationship for the reactivity of carboxylic acids with diazodiphenylmethane in protic and aprotic solvents

2009 ◽  
Vol 74 (12) ◽  
pp. 1335-1357 ◽  
Author(s):  
Gordana Uscumlic ◽  
Jasmina Nikolic
Keyword(s):  
Solvent Effects ◽  
Kinetic Data ◽  
Chemical Reactivity ◽  
Linear Regression Analysis ◽  
Quantitative Relationship ◽  
Solvation Energy ◽  
Multiple Linear Regression Analysis ◽  
Reaction Rates ◽  
Solvation Models ◽  
Linear Solvation Energy

Solvent effects on the reactivity of cycloalkenecarboxylic, cycloalkeneacetic, 2-substituted cyclohex-1-enecarboxylic, 2-substituted benzoic, 2-substituted cyclohex-1-eneacetic, 2-substituted phenylacetic, 2-phenylcyclohex-1-enecarboxylic, 2-phenylbenzoic and 2-phenylacrylic acids with diazodiphenylmethane (DDM) were investigated. In order to explain the kinetic results through solvent effects, the second-order rate constants for the reaction of the examined acids with DDM were correlated using the Kamlet-Taft solvatochromic equation. The correlations of the kinetic data were realized by means of multiple linear regression analysis and the solvent effects on the reaction rates were analyzed in terms of the contributions of the initial and the transition state. The signs of the equation coefficients support the proposed mechanism. Solvation models for all the investigated acids are suggested. The quantitative relationship between the molecular structure and the chemical reactivity is also discussed.

scholarly journals A linear solvation energy relationship study for the reactivity of 2-substituted cyclohex-1-enecarboxylic and 2-substituted benzoic acids with diazodiphenylmethane in aprotic and protic solvents

2007 ◽  
Vol 72 (12) ◽  
pp. 1217-1227 ◽  
Author(s):  
Jasmina Nikolic ◽  
Gordana Uscumlic
Keyword(s):  
Solvent Effects ◽  
Rate Constants ◽  
Chemical Reactivity ◽  
Linear Regression Analysis ◽  
Quantitative Relationship ◽  
Multiple Linear Regression Analysis ◽  
Reaction Rates ◽  
Benzoic Acids ◽  
Linear Solvation Energy ◽  
Substituted Benzoic Acids

The rate constants for the reaction of 2-substituted cyclohex-1-enecarboxylic acids and the corresponding 2-substituted benzoic acids with diazodiphenylmethane were determined in various aprotic solvents at 30 ?C. In order to explain the kinetic results through solvent effects, the second order rate constants of the reaction of the examined acids were correlated using the Kamlet-Taft solvatochromic equation. The correlations of the kinetic data were carried out by means of multiple linear regression analysis and the solvent effects on the reaction rates were analyzed in terms of the contributions of the initial and transition state. The signs of the equation coefficients support the proposed reaction mechanism. The quantitative relationship between the molecular structure and the chemical reactivity is discussed, as well as the effect of geometry on the reactivity of the examined molecules.

scholarly journals The comparative study of linear solvatation energy relationship for the reactivity of pyridine carboxylic acids with diazodiphenylmethane in protic and aprotic solvents

2012 ◽  
Vol 77 (10) ◽  
pp. 1311-1338 ◽  
Author(s):  
Sasa Drmanic ◽  
Jasmina Nikolic ◽  
Aleksandar Marinkovic ◽  
Bratislav Jovanovic
Keyword(s):  
Solvent Effects ◽  
Kinetic Data ◽  
Aprotic Solvent ◽  
Isonicotinic Acid ◽  
Linear Regression Analysis ◽  
Multiple Linear Regression Analysis ◽  
Reaction Rates ◽  
Aprotic Solvents ◽  
Pyridine Carboxylic ◽  
The Comparative Study

Protic and aprotic solvent effects on the reactivity of picolinic, nicotinic and isonicotinic acid, as well as of some substituted nicotinic acids with diazodiphenylmethane (DDM) were investigated. In order to explain the kinetic results through solvent effects, the second-order rate constants for the reaction of the examined acids with DDM were correlated using the Kamlet-Taft solvatochromic equation. The correlations of the kinetic data were carried out by means of the multiple linear regression analysis and the solvent effects on the reaction rates were analyzed in terms of the contributions of the initial and the transition state. The signs of the equation coefficients support the already known reaction mechanism. The solvatation models for all the investigated acids are suggested and related to their specific structure.

Solvent effects in organic chemistry — recent developments

1988 ◽  
Vol 66 (11) ◽  
pp. 2673-2686 ◽  
Author(s):  
Michael H. Abraham ◽  
Priscilla L. Grellier ◽  
Jose-Luis M. Abboud ◽  
Ruth M. Doherty ◽  
Robert W. Taft
Keyword(s):  
Organic Chemistry ◽  
Solvent Effects ◽  
Linear Regression Analysis ◽  
Multiple Linear Regression Analysis ◽  
Reaction Rates ◽  
Distribution Coefficients ◽  
Solvent Interactions ◽  
Conformational Equilibria ◽  
Recent Developments ◽  
Solubility Of Gases

Solvent effects on a number of different processes have been surveyed, and results of the application of multiple linear regression analysis are discussed. The processes examined include examples of solubility of gases or vapours, distribution coefficients of solutes between water and a series of solvents, and solvent effects on conformational equilibria, on keto–enol tautomerism, and on reaction rates. It is shown that two particular equations, that due to Koppel and Palm and extended by Makitra and Pirig, and that due to Abraham, Kamlet, and Taft, can cope quite satisfactorily with solvent effects on these various processes. It is pointed out that interpretation of parameters obtained from equations that involve macroscopic quantities such as ΔG≠ or ΔG0 is not necessarily straightforward, and that some model is needed in order to interpret these macroscopic quantities in terms of microscopic quantities that can characterise, for example, solute–solvent interactions.

scholarly journals The influence of the solvent on organic reactivity. Part II. Hydroxylic solvent effects on the reaction rates of diazodiphenylmethane with 2-(2-substituted cyclohex-1-enyl)acetic and 2-(2-substituted

2004 ◽  
Vol 69 (8-9) ◽  
pp. 601-610 ◽  
Author(s):  
Jasmina Nikolic ◽  
Gordana Uscumlic ◽  
Vera Krstic
Keyword(s):  
Hydrogen Bond ◽  
Solvent Effects ◽  
Linear Regression Analysis ◽  
Solvent Polarity ◽  
Multiple Linear Regression Analysis ◽  
Reaction Rates ◽  
Hydrogen Bond Donor ◽  
Initial State ◽  
Hydrogen Bond Acceptor ◽  
Acetic Acids

The rate constants for the reaction of diazodiphenylmethane with 2-(2-substituted cyclohex-1-enyl)acetic acids and 2-(2-substituted phenyl)acetic acids, previously determined in seven hydroxylic solvents, were correlated using the total solvatochromic equation, of the form logk = logk0 + s?*+ a? + b?, the two-parameter model, logk=logk0 + s?*+ a? and a single parameter model logk = logk0 + b?, where ?*is a measure of the solvent polarity, ? represents the scale of solvent hydrogen bond acceptor basicities and ? represents the scale of solvent hydrogen bond donor acidities. The correlations of the kinetic data were carried out by means of multiple linear regression analysis and the solvent effects on the reaction rates were analyzed in terms of initial state and transition state contributions.

scholarly journals Reactivity of cyclohex-1-enylcarboxylic and 2-methylcyclohex-1-enylcarboxylic acids with diazodiphenylmethane in aprotic solvents

2000 ◽  
Vol 65 (12) ◽  
pp. 839-846
Author(s):  
Jasmina Nikolic ◽  
Gordana Uscumlic ◽  
Vera Krstic
Keyword(s):  
Hydrogen Bond ◽  
Rate Constants ◽  
Kinetic Data ◽  
Linear Regression Analysis ◽  
Spectroscopic Method ◽  
Reaction Rates ◽  
Aprotic Solvents ◽  
Experimental Conditions ◽  
Hydrogen Bond Acceptor ◽  
Protic Solvents

Rate constants for the reaction of diazodiphenylmethane with cyclohex-1-enylcarboxylic acid and 2-methylcyclohex-1-enylcarboxylic acid were determined in nine aprotic solvents, as well as in seven protic solvents, at 30?C using the appropriate UV-spectroscopic method. In protic solvents the unsubsituted acid displayed higher reaction rates than the methyl-substituted one. The results in aprotic solvents showed quite the opposite, and the reaction rates were considerably lower. In order to explain the obtained results through solvent effects, reaction rate constants (k) of the examined acids were correlated using the total solvatochromic equation of the form: log k=logk0+s?*+a?+b?, where ?* is the measure of the solvent polarity, a represents the scale of the solvent hydrogen bond donor acidities (HBD) and b represents the scale of the solvent hydrogen bond acceptor basicities (HBA). The correlation of the kinetic data were carried out by means of multiple linear regression analysis and the opposite effects of aprotic solvents, as well as the difference in the influence of protic and aprotic solvents on the reaction of the two examined acids with DDM were discussed. The results presented in this paper for cyclohex-1-enylcarboxylic and 2-methylcyclohex-1-enylcarboxylic acids were compared with the kinetic data for benzoic acid obtained in the same chemical reaction, under the same experimental conditions.

scholarly journals Effects of solvent and structure on the reactivity of 2-substituted nicotinic acids with diazodiphenylmethane in aprotic solvents

2012 ◽  
Vol 77 (5) ◽  
pp. 569-579
Author(s):  
Sasa Drmanic ◽  
Jasmina Nikolic ◽  
Bratislav Jovanovic
Keyword(s):  
Rate Constants ◽  
Substituent Effect ◽  
Kinetic Data ◽  
Reaction Rate ◽  
Linear Regression Analysis ◽  
Multiple Linear Regression Analysis ◽  
Aprotic Solvents ◽  
Solvent Interaction ◽  
Complete Form ◽  
Solute Solvent Interaction

The rate constants for the reactions of diazodiphenylmethane (DDM) with 2-substituted nicotinic acids in nine aprotic solvents at 30?C were determined. The obtained second order rate constants in aprotic solvents were correlated using the Kamlet?Taft solvatochromic equation in the complete form: log k = log k0 + s?* + a??+ b?. The correlations of the kinetic data were realized by means of multiple linear regression analysis. The obtained results were analyzed in terms of the initial and the transition state of the reaction and compared with previously determined kinetic data for nicotinic acid. The signs of the equation coefficients (s, a and b) are in agreement with the reaction mechanism and the influence of the solvent on the reaction rate is discussed based on the correlation results. The mode of the transmission of the substituent effect is discussed in light of the contribution of solute?solvent interaction to the reactivity of the acid. The substituent effect was additionally analyzed by the Hammett equation, log k = p??+ log k0.

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