Classification of organic solvents based on correlation between dielectric ? parameter and empirical solvent polarity parameter E N T

Abstract

It is proposed that the ratio p2/V, from electrostatic solvation theory, be used to designate solvent polarity; p is t h e dipole moment and V the molar volume. The 101 solvents analysed can be divided into four classes (and two subclasses) by means of t h e correlation between the dielectric B parameter (proportional to p2/V) and the empirical solvent polarity parameter € :. Although t h e method proposed is very simple, t h e results agree very well with those obtained by a much more complex multivariate statistical method (M. Chastrette, M. Rajzmann, M. Chanon and K. F. Purcell, J. Am. Chern. SOC., 1985, 107, 1). Moreover some solvents, that are apparently nonconformist under t h e Chastrette criteria, can be classified in line with their molecular properties under the method described here.

Chemometrics for Selection, Prediction, and Classification of Sustainable Solutions for Green Chemistry—A Review

“…Interestingly, these classifications are carried out for various objects (types of solvents) using different chemometric tools, for instance, PCA, KNN (k-nearest neighbours method), Parker-Reichardt classification, CP-ANN (counter-propagation artificial neural network), ANN (artificial neural network), PCA, and CA, obtaining similar results. An example may be the study performed by Dutkiewicz [44] using the Parker-Reichardt classification, whose results highly correspond to those obtained by a more complex multivariate statistical method presented by M. Chastrette et al [43]. Moreover, there are applications with few tools applied.…”

Reappraisal of Empirical Solvent Polarity Scales for Organic Solvents

“…This crucial aspect was not discussed in the underestimated work of Dutkiewicz. Also, the origin of the different plots as a function of the property of solvent could not really be explained [41] …”

“…It is worth mentioning that the use of V m as an appropriate variable in combination with the dipole moment of the solvent molecule μ for interpretation of E T (30) solvent polarity (μ 2 /V m ) has already been suggested by Dutkiewicz. [41] Separate linear correlations of μ 2 /V m with the E T N parameter for various types of solvents regarding their chemical properties such as nonpolar, aprotic or protic were found. Therefore, the product μ 2 • N also linearly correlates with E T N , because N is the reciprocal to V m .…”

“…Also, the origin of the different plots as a function of the property of solvent could not really be explained. [41] Starting from the consideration that E T (30) is a function of N, [35] we reinvestigated this relationship for alcohols using an extended data set as shown in Figure 2.…”

“…The role of N of pure organic solvents on empirical polarity parameters is still underestimated and is a central subject of this study. Only occasionally has this aspect of V m or N already been considered in the interpretation of E T (30) or other solvatochromic data [1c,11,35,40,41] …”