MULTIVARIATE ERROR ANALYSIS OF INCREMENT METHODS FOR CALCULATING THE OCTANOL WATER-PARTITION COEFFICIENT/

The performance of seven group contribution methods for calculating th e octanol/water partition coefficient (log K-ow) is comparatively anal yzed with a test set of 650 compounds containing the elements C, H, ha logen, N, O, P and S. The degree of agreement with experimental data i s characterized by r(2) values from 0.87 to 0.98, with individual erro rs being above two orders of magnitude. Principal component analysis o f the method errors reveals significant differences between the indivi dual schemes. The discussion concentrates on trends of method-specific errors associated with certain chemical classes.