A QSPR study of hydrophobicity of phenols and 2-(aryloxy-alpha-acetyl)-phenoxathiin derivatives using the topological index ZEP

The molecular hydrophobicity (RMO) of several newly synthesized phenoxathiin derivatives and of phenols with congeneric structures have been recently correlated with some simple physico-chemical calculated parameters of compounds: the water solubility (log Sw ); the partition coefficient (log P ); the Gibbs energy of formation (∆Gf ), and the aromaticity index (HOMA) [Beteringhe, A., Radutiu, A. C., Constantinescu, T., Patron, L. and Balaban, A. T., Quantitative Structure-Property Relationship (QSPR) study of the hydrophobicity of phenols and 2-(aryloxy-α-acetyl)- phenoxathiin derivatives, Rev. Chim. (Bucures ̧ti) , 59 (2008), No. 11, 1175–1179]. The best correlation was found as a biparametric regression equation in terms of log Sw and HOMA, which cannot be improved by adding one or two of the parameters aforementioned.

In the present work we describee the weighted electronic distance based topological index (ZEP) and then use it for QSPR studies of RMO in combination with logSw, logP, ∆Gf and HOMA. Most of the three parameter QSPR correlations of RMO are significantly improved by involving the theoretical parameter ZEP.