Physicochemical properties/descriptors governing the solubility and partitioning of chemicals in water-solvent-gas systems. Part 1. Partitioning between octanol and air

• Published in: SAR and QSAR in environmental research 2006-06, Vol.17 (3), p.285-297
• Main Authors: Raevsky, O. A., Grigor'ev, V. J., Raevskaja, O. E., Schaper, K.-J.
• Format: Article
• Language: English
• Subjects: 1-Octanol - chemistry; Air; Gas-octanol-water; Gases - chemistry; H-bond factors; Molecular polarisability; Organic Chemicals - chemistry; Partition; Quantitative Structure-Activity Relationship; Similarity; Software; Solubility; Solvents - chemistry; Water - chemistry
• ISSN: 1062-936X; 1029-046X
• DOI: 10.1080/10659360600787742

QSPR analyses of a data set containing experimental partition coefficients in the three systems octanol-water, water-gas, and octanol-gas for 98 chemicals have shown that it is possible to calculate any partition coefficient in the system 'gas phase/octanol/water' by three different approaches: (1) from experimental partition coefficients obtained in the corresponding two other subsystems. However, in many cases these data may not be available. Therefore, a solution may be approached (2), a traditional QSPR analysis based on e.g. HYBOT descriptors (hydrogen bond acceptor and donor factors, ΣCa and ΣCd, together with polarisability α, a steric bulk effect descriptor) and supplemented with substructural indicator variables. (3) A very promising approach which is a combination of the similarity concept and QSPR based on HYBOT descriptors. In this approach observed partition coefficients of structurally nearest neighbours of a compound-of-interest are used. In addition, contributions arising from differences in α, ΣCa, and ΣCd values between the compound-of-interest and its nearest neighbour(s), respectively, are considered. In this investigation highly significant relationships were obtained by approaches (1) and (3) for the octanol/gas phase partition coefficient (log L og ).