Correlation and prediction of the solubility of Buckminsterfullerene in organic solvents; estimation of some physicochemical properties
Abstract
The solubilities of Buckminsterfullerene, C60, in 20 organic solvents have been transformed into water–solvent partition coefficients and the latter, as log P values, analysed by the Abraham solvation equation. Our analysis indicates that a water solubility of 10−18 mol dm−3 is the optimum value. The solubilities can be transformed into air–solvent partitions, L, using optimum values of the saturated vapour concentration, 10−24 mol dm−3, and the air–water partition coefficient, 10−6. A total of 41 log P and log L values were thus processed to obtain the Abraham solvation descriptors for C60. It is shown that C60 is dipolar/polarisable, has no hydrogen bond acidity, but is a slightly stronger hydrogen bond base than compounds such as acetophenone. The descriptors indicate that C60 behaves rather like a polyalkene rather than an aromatic system. Various properties of C60 can be predicted from the solvation descriptors; C60 is very lipophilic, is distributed between blood and brain largely into the brain, and is taken up by plant matrices from the air or from water almost quantitatively.