ChemInform Abstract: Factor Analysis of Solvent Effects on Reactions. Application to the Claisen Rearrangement.

On the basis of factor analysis of data matrices containing 35 empirical and non-empirical parameters for 85 solvents (or a limited matrix of 20 parameters for 51 solvents), an orthogonal set of parameters with normed normal distribution has been suggested which characterizes influence of the solvents on chemical processes. A four-parameter equation has been suggested for description of the solvent effect in the form A = A0 + aAP + bBP + eEP + pPP, where AP, BP, EP, PP are newly introduced parameters expressing individual types of interactions between solvent and solute. A comparison has been carried out of these parameters with those defined earlier. The new set of parameters was tested with 22 examples taken from literature. The correlations obtained show higher or comparable agreement as compared with those carried out earlier. Values of the regression coefficients make it possible to discuss the reaction mechanisms from the point of view of solvent effects.

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The Claisen Rearrangement - Part 2: Impact Factor Analysis of the Claisen Rearrangement, in Batch and in Flow

ChemBioEng Reviews ◽

10.1002/cben.201400022 ◽

2014 ◽

Vol 1 (6) ◽

pp. 244-261 ◽

Cited By ~ 8

Author(s):

Volker Hessel ◽

Elnaz Shahbazali ◽

Timothy Noël ◽

Sergei Zelentsov

Keyword(s):

Factor Analysis ◽

Impact Factor ◽

Claisen Rearrangement

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The Hammett substituent constants and effects of medium

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19862143 ◽

1986 ◽

Vol 51 (10) ◽

pp. 2143-2150 ◽

Cited By ~ 6

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.

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