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

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.

2012 ◽  
Vol 77 (10) ◽  
pp. 1311-1338 ◽  
Author(s):  
Sasa Drmanic ◽  
Jasmina Nikolic ◽  
Aleksandar Marinkovic ◽  
Bratislav Jovanovic

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.


2004 ◽  
Vol 69 (8-9) ◽  
pp. 601-610 ◽  
Author(s):  
Jasmina Nikolic ◽  
Gordana Uscumlic ◽  
Vera Krstic

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.


2007 ◽  
Vol 72 (12) ◽  
pp. 1217-1227 ◽  
Author(s):  
Jasmina Nikolic ◽  
Gordana Uscumlic

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.


2009 ◽  
Vol 74 (12) ◽  
pp. 1335-1357 ◽  
Author(s):  
Gordana Uscumlic ◽  
Jasmina Nikolic

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.


2018 ◽  
Vol 14 (1) ◽  
Author(s):  
Giovani Herman ◽  
Inggriani Elim ◽  
Victorina Z. Tirayoh

Recent developments in the economy in Indonesia have led to an increasingly increasing accounting role that demands accounting that can provide the financial information needed by society in making economic decisions. It is now increasingly recognized by entrepreneurs. Accounting also greatly facilitates the smoothness of management tasks. This research was conducted at 30 travel agency service companies (travel) located in Manado city. The purpose of this research is to examine the influence of the mastery of accounting and entrepreneurial innovation on managerial performance in travel agency services company in Manado city. The analytical method used is multiple linear regression analysis method with the help of SPSS 12.0 software. Based on multiple linear regression analysis. The result of the research shows that Accounting Mastery (X1) has an effect on Managerial Performance (X2) in Travel Service Company in Manado City, and Entrepreneurial Innovation also has an effect on Managerial Performance in Service Company of Travel Bureau in Manado City. This shows that the variable of Accounting Mastery (X1) and Entrepreneurial Innovation (X2) together have a significant influence on Managerial Performance variables (Y). at Travel Service Company (Travel) in Manado City. so it can be concluded that Ha accepted and rejected H0 or can be said that the variable of Accounting Mastery and Entrepreneurial Innovation Variables affect the variable of Managerial Performance in Travel Service Company (Travel) d Manado City.Keywords: Accounting, Innovation, Entrepreneurship, Managerial Performance


ChemInform ◽  
1989 ◽  
Vol 20 (20) ◽  
Author(s):  
M. H. ABRAHAM ◽  
P. L. GRELLIER ◽  
J.-L. M. ABBOUD ◽  
R. M. DOHERTY ◽  
R. W. TAFT

Author(s):  
Ary Sutrischastini ◽  
Ratna Setyani

This research goal is to identification and evaluation influence of work motivation and work environment to employee’s performance in BAPPEDA Kabupaten Wonosobo. The object of this research is 37 employees of Badan Perencanaan Pembangunan Kabupaten Wonosobo. And the location of this research is at Badan Perencanaan Pembangunan Kabupaten Wonosobo. The analysis used is test validity, reliability testing, and test the hypothesis, with the help of the computer program SPSS version 17, using multiple linear regression analysis. Based on calculations of data and analysis used, the regression equation is obtained: Y = 11.733 + 0.320 X1 +0.334 X2 + ε, by using the equation regression analytical method can conclude that (X1) take effect positively against employees performance. With t value in amount of 2,219 (bigger than t in table in amount of 1,690) and significance value in amount of 0,33. By applying significance limited value in amount of 0,05, it means, hypothesis that claim if work motivation take effect against employees performance can be accepted. There is a positive and significant correlation between work environment variables (X2) against employees. With t value in amount of 2,219 (bigger than t in table in amount of 1,690) and significance value in amount of 0,33 (smaller than 0,5). Simultaneously, work motivation take effect positively and significantly against employees performance with the F value in amount of 11,562 (bigger than 0.05), then obtained significance value 0.000. It can be concluded that the work motivation and work environment has a positive and significant influence on employee performance in BAPPEDA Kabupaten Wonosobo.


Author(s):  
Eka Ambara Harci Putranta ◽  
Lilik Ambarwati

The study aims to analyze the influence of internal banking factors in the form of: Capital Adequency Ratio (CAR), Financing to Deposit Ratio (FDR) and Total Assets (TA) to Non Performing Financing at Sharia Banks. This research method used multiple linear regression analysis with the help of SPSS 16.00 software which is used to see the influence between the independent variables in the form of Capital Adequacy Ratio (CAR), Financing to Deposit Ratio (FDR) and Total Assets (TA) to Non Performing Financing. The sample of this study was 3 Islamic Commercial Banks, so there were 36 annual reports obtained through purposive sampling, then analyzed using multiple linear regression methods. The results showed that based on the F Test, the independent variable had an effect on the NPF, indicated by the F value of 17,016 and significance of 0,000, overall the independent variable was able to explain the effect of 69.60%. While based on the partial t test, showed that CAR has a significant negative effect, Total assets have a significant positive effect with a significance value below 0.05 (5%). Meanwhile FDR does not affect NPF.


2020 ◽  
Vol 28 (1) ◽  
pp. 35-50
Author(s):  
Dewi Kusuma Wardani ◽  
Ratih Ranika Putri Utami

This study aims to determine the effect of transparency in financial management of village funds and community empowerment on community welfare in Sidoharjo Village, Tepus District, Gunungkidul Regency. This research method uses quantitative descriptive methods and primary data using questionnaires. This study took a sample of residents who were divided into 11 hamlets in Sidoharjo Village, Tepus District, Gunung kidul Regency. The sampling technique is stratified random sampling. Data collection is done by distributing questionnaires directly to people’s homes, attending social gatherings and routine meetings held by community members. It aims to obtain more data from respondents directly. The number of questionnaires processed was 120 questionnaires. Data were analyzed using multiple linear regression analysis. The results of this study indicate that community empowerment has a positive effect on the welfare of the people of Sidoharjo Village, Tepus District, Gunungkidul Regency, while transparency in financial management of village funds does not affect the welfare of the community in Sidoharjo Village, Tepus District, Gunungkidul Regency.


2017 ◽  
Vol 24 (1) ◽  
pp. 35-53
Author(s):  
Sulastiningsih Sulastiningsih ◽  
Intan Ayu Candra

The purpose of this study is to prove: (1) Time pressure, locus of control, the action of supervision and materiality partially affect the premature termination of the audit procedures (2) Time pressure, locus of control, supervision and materiality simultaneously affect the premature termination on the audit procedures. This research was conducted in Public Accountant firm in Yogyakarta region of which total 12 samples of KAP, by distributing 105 questionnaires, and 57 questionnaires were returned (54%). 34 of the returned questionnaires can be processed (34%). The samples in this study were determined by using non-probability sampling, one of purposive sampling methods. Data analysis consisted of: (1) validity test, reliability test and classical assumption. The result showed that the instruments used are quite reliable and valid (2) multiple linear regression analysis. The results are (a) Some of independent variables partially affect premature termination of the audit procedure, while the action of supervision does not influence premature termination of audit procedures (b) All independent variables influence simultaneously to the premature termination of the audit procedures (c) All independent variables showed that as much as 55% it affects on premature termination of the audit procedures, the rest of it are influenced by other variables. (3) Friedman Test. The result shows that there are order of priority of audit procedures being terminated.


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