Kamlet-Taft multiparameter

The method of linear solvation energy (LSER), based on the Kamlet-Taft multiparameter scale (10) has been successfully exploited to study retention in LC. The LSER approach, when applied to phase-transfer processes, correlates a general solute property (SP), such as logarithmic capacity factor, with parameters of the solute and both the mobile and stationary phases ... 

Dealing with this type of multiparameter correlation analysis, a series of twelve articles entitled Solubility Properties in Polymers and Biological Media was published by Kamlet, Taft, Abraham et al. (Part 1 [273]...Part 12 [274]), as well as another series entitled Solute Solvent Interactions in Chemical and Biological Systems (Part 4 [358]... Part 7 [359]). The application of the LSER equation (7-58) to the prediction of solubilities of organic nonelectrolytes in water, blood, and other body tissues has been reviewed [286],... 

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). 

Both Kamlet, Abboud, and Taft et al. s [224, 226] and Swain et aVs [265] multiparameter solvent effect treatments have an inherent weakness in so far as the solvent parameters a, and n as well as and are averaged and statistically optimized parameters the former are derived from various types of solvatochromic indicator dyes. 

Many different solvent parameters and multiparameter equations have been introduced in this Chapter 7. Certainly, only a few of them will survive the test of applicabihty and aeeeptanee by organic chemists. Indeed, the preference for certain time-tested solvent seales and multiparameter treatments is already clearly discernible. Amongst the one-parameter seales, the t(30) or Ej seale and the DN scale have frequently been used, while the Kamlet-Abboud-Taft (KAT) LSER approach seems to be the most widely applied multiparameter approach. 

Abraham, in collaboration with Taft, Kamlet, and Abboud, has made an interesting attempt to characterize the nature of a solvent in terms of its H-bond donor ability (HBD or), H-bond acceptor ability (HBA jS), and its specific dipolarity/polarizabiUty (jt ). He has used these parameters in multiparameter relationships to analyze medium effects on a variety of chemical processes. Briefly, the HBD propensities (a) were obtained from the enhanced sol-vatochromism of the t(30) probe relative to 4-nitroanisole, the HBA propensities (j8) from the enhanced solvatochromism of 4-nitroaniline relative to N,N-diethyl-4-nitroaniline in HBA solvents, and the rt values from solvent effects on the n n transition of nitro-substituted aromatic compounds. For a more detailed discussion of these parameters and their apphcations, the reader is referred to the original literature. ... 

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