Statistical analysis of solvatochromic shift data

Abstract

Principal component (p.c.) analysis combined with a cross-validation technique (c.v.) was used in the analysis of some data sets composed of solvatochromic shift data for non-hydrogen bonding indicators. The data were basically the same as earlier used by Kamlet et al. to define the π* solvent polarity scale. The c.v. showed that to adequately describe the data a two-component p.c. model was needed and consequently two parameters θ_1k and θ_2k were determined for each solvent k. The performance of these solvent parameters was compared with the π* scale.