Koppel-Palm solvent

Equations containing a number of solvent parameters in linear or multiple linear regression and expressing the effect of the solvent on the rate of the reaction or the thermodynamic equilibrium constant. See Ej Values Kamlet-Taft Solvent Parameter Koppel-Palm Solvent Parameter Z Value... 

ENZYME KINETIC EQUATIONS MICHAELIS CONSTANT UNI UNI MECHANISM Koppel-Palm solvent parameters,... 

KAMLET-TAET SOLVENT PARAMETER KOPPEL-PALM SOLVENT PARAMETER ZVALUE LINEAR STRAIN Line formula,... 

Koppel-Palm solvent parameters Parameters to measure separately the ability of a solvent to enter into nonspecific solvent-solute interactions (permittivity, , and refractive index, nD) and specific solvent-solute interaction (solvent basicity or NUCLEOPHILICITY B and solvent acidity or ELECTROPHILICITY E) as contributing to overall solvent POLARITY. 

GRUNWALD-WlNSTEIN EQUATION KAMLET-TAFT SOLVENT PARAMETERS KOPPEL-PALM SOLVENT PARAMETERS SOLVOPHOBICITY PARAMETER Z-VALUE. 

Recently the data concerning to interaction of propanthiole with chlorine dioxide in 8 solvents have been published [1], In this work it was shown, that the dependence of process rate from solvents properties is satisfactory described for seven solvents, after the exclusion of data for ethyl acetate, by the Koppel-Palm four parameters equation (coefficient of multiple correlation R 0,96) at determining role of medium polarity (coefficient of pair correlation between lg(k) and (s - l)/(2e + 1) - r 0.90). Chemical mechanism of the reaction including the formation of ion-radical RS H and radical RS has been proposed by authors [ ] ... 

Correlation analysis of solvent effects on the heterolysis of p-methoxyneophyl tosyl-ate has been performed by using the Koppel-Palm and Kamlet-Taft equations. The reaction rate is satisfactorily described by the electrophilicity and polarity parameters of solvents, but a possible role for polarizability or nucleophilicity parameters was also examined. 

For reviews of solvent polarity scales, see Abraham Grellier Abboud Doherty Taft Can. J. Chem. 1988,66. 2673-2686 Kamlet Abboud Taft Prog. Phys. Org. Chem. 1981,13,485-630 Shorter Correlation Analysis of Organic Reactivity Wiley New York, 1982, pp. 127-172 Reichardt, Ref. 386 Reichardt Dimroth, Ref. 386 Abraham Prog. Phys. Org. Chem. 1974, II, I -87 Koppel Palm, in Chapman Shorter Advances in Linear Free Energy Relationships, Plenum New York, 1972, pp. 203 280 Ref. 384. See also Chastrette Carrclto Tetrahedron 1962,38, 1615 Chastrette Rajzmann Chanon Purcell J. Am. Chem. Soc. 1965,107, 1. 

Solvent effects on silatranes are found to be better described by Koppel-Palm and Taft-Kamlet solvent parameters. A good relationship has been established for and Si shifts for 1-methylsilatrane ... 

The rate of reaction between benzoic acid and diazo-diphenylmethane in 44 non-HBD solvents correlates significantly with all four Koppel-Palm parameters of Eq. (7-50), according to Eq. (7-52) with = 44, r = 0.976, and standard deviation s = 0.188 [15, 116] cf also [117]. 

Recently, a statistical treatment of 31 different solvent parameter scales was carried out by Palm et al. [348], in order to And the minimum number of solvent parameters necessary for an adequate multiparameter description of solvent-dependent processes. Numerous applications of the Koppel-Palm Eq. (7-50) and modifications thereof to the correlation analysis of many solvent-dependent processes, taken from different areas of... 

According to the Lorentz-Lorenz equation (4.3.21) for the molar refraction at optical frequencies, Y is directly proportional to the molecular polarizability p. The Koppel-Palm equation has also been applied to the analysis of solvent effects on thermodynamic quantities related to the solvation of electrolytes [48, 49]. In the case of the systems considered in table 4.11, addition of the parameter X to the linear equation describing the solvent effect improves the quality of the fit to the experimental data, especially in the case of alkali metal halide electrolytes involving larger ions. The parameter Y is not important for these systems but does assist in the interpretation of other thermodynamic quantities which are solvent dependent [48, 49]. Addition of these parameters to the analysis is only possible when the solvent-dependent phenomenon has been studied in a large number of solvents. 

Perhaps the most successful application of the Koppel-Palm model to date is to be attributed to Chapman et al [Ch 74], who used it to describe the solvent dependence of the rate of the reaction between benzoic acid and diazophenylmet-hane. The rate constants determined in 24 different solvents were processed, and a very good correlation was obtained. However, processing of the same data on the basis of the model of Krygowski and Fawcett resulted in an even better correlation... 

Krygowski and Fawcett described the variation of the physico-chemical parameter g, reflecting the solvent effect, in an analogous manner to that in the first half of the equation of the Koppel-Palm model, but as a linear function of only two independent complementary terms ... 

Numerous authors have devised multiple linear regression approaches to the eorrelation of solvent effects, the intent being to widen the applieability of the eorrelation and to develop insight into the moleeular factors controlling the eorrelated proeess. For example, Zilian treated polarity as a eombination of effeets measured by molar refraction, AN, and DN. Koppel and Palm write... 

Palm s group has continued to develop statistical procedures for treating solvent effects. In a previous paper, a set of nine basic solvent parameter scales was proposed. Six of them were then purifled via subtraction of contributions dependent on other scales. This set of solvent parameters has now been applied to an extended compilation of experimental data for solvent effects on individual processes. Overall, the new procedure gives a signiflcantly better flt than the well-known equations of Kamlet, Abboud, and Taft, or Koppel and Palm. 

Use of the Palm-Koppel equation (72MI1 77MI1 88MI1) led to a good correlation (r = 0.986) (91ZPK1052) between the constants of the ring-chain equilibrium 13A 13B (X = H) measured ( H-NMR) in ten deuter-ated solvents and the sum of solvent polarity, polarizability, general acidity,... 

Because of the different effects of electrophilic solvation of the various negative charges (i.e. Cl- for Y, "OTs for Tots I" for Z, 0 for Ej), direct comparisons between the various scales should be done cautiously. A wide variety of correlations giving clear indications of trends, has been reported by Reichardt and Dimroth (1968), but the significance of a recent general survey of scales of solvent polarity is doubtful, because of the many parameters used in the correlations (Fowler et al., 1971). The multi-parameter approach has also been adopted and reviewed by Koppel and Palm (1972). 

A more rigorous approach has been suggested by Koppel and Palm [6, 112], who argue that a complete description of all solute/solvent interactions must include both non-specific and specific effects. They proposed the general four-parameter equation (7-50), which relates the variation of a given property A to two non-specific (T and P) and two specific characteristics of the solvent E and B). 

The procedure for parameterization of solvent electrophilicity has been criticized, mainly because it was found that the use of t(30) instead of E in the multiple regression treatment of solvent effects is often quite successful see reference [15, 116] for examples. It has been shown that values of t(30) and E are linearly correlated, at least for solvents with an t(30) value of greater than ca. 40 kcal/mol [178]. This calls into question the value of Koppel and Palm s division of t(30) into pure electrophilicity effects and non-specific effects by means of Eq. (7-51). 

Another important treatment of multiple interacting solvent effects, in principle analogous to Eq. (7-50) but more precisely elaborated and more generally applicable, has been proposed by Kamlet, Abboud, and Taft (KAT) [84a, 224, 226], Theirs and Koppel and Palm s approaches have much in common, i.e. that it is necessary to consider non-specific and specific solute/solvent interactions separately, and that the latter should be subdivided into solvent Lewis-acidity interactions (HBA solute/HBD solvent) and solvent Lewis-basicity interactions (HBD solute/HBA solvent). Using the solvato-chromic solvent parameters a, and n, which have already been introduced in Section 7.4 cf. Table 7-4), the multiparameter equation (7-53) has been proposed for use in so-called linear solvation energy relationships (LSER). 

B empirical parameter of solvent Lewis basicity (Palm and Koppel) ... 

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