The RP-HPLC measurement and QSPR analysis of log Po/w values of several Pt(II) complexes

The n-octanol/water partition coefficient, log Po/w, for a set of 24 Pt(II)-complexes was estimated by means of reversed-phase high performance liquid chromatography (RP-HPLC) technique using a C18 (ODS, octadecyl silane) column as a stationary phase and water/methanol mixtures as mobile phases. Based on the known log Po/w of several Pt(II)-complexes, we set a method to correlate the partition coefficient of this kind of complexes with the corresponding retention parameters. The best result was obtained from extrapolation to 0% of the organic modifier (MeOH) of the aqueous eluant. A quantitative structure–property relationship (QSPR) was constructed using molecular descriptors derived from density functional theory (DFT) calculations, which was found to correlate and predict these values with good accuracy. The use of DFT calculations is required because group-additive methods fail due to lack of values for appropriate fragments for many Pt(II)-complexes.