Development of a method to model the mixing energy of solutions using COSMO molecular descriptors linked with a semi-empirical model using a combined ANN-QSPR methodology

Abstract

A methodology linking the interaction parameters of a semi-empirical model to COSMO molecular descriptors to represent the hE(x) is presented. A database of 4395 values of ester-alkane is used to check the procedure. Relationships are established for the model coefficients, ai1,i2,…ip, although only for a12 and for a second parameter k21, which governs the asymmetry of the representation of the mixing process. A discretization of the σ-profile and its statistical moments constitute two descriptors, as a vector, Sσ-profilej and Sσ-momentp, for a12. A third molecular descriptor/vector, is described for k21, based on the divergence of Kullback-Leibler and the molecules size, which is presented for the first time as: SRσ-profile=A1,A2,DKL[p1(σ)||p2(σ)],DKL[p2(σ)||p1(σ)] The clustering of systems in a a12/k21-space is predictable with molecular descriptors in relation to their main interactions. An ANN-QSPR binomial estimates the parameters a12 and k21 from molecular descriptors. The methodology generalizes the procedure, acceptably representing the energetic effects of solutions (R2 > 0.9).