Can near Infrared-Absorption Spectra Explain the Different Diffusivities of Substituted Benzenes and Alcohols in Octan-1-Ol?

The considerable diffusivity difference of substituted benzenes and of alcohols in octan-1-ol¹ suggests a strong influence of specific solute-solvent interactions (hydrogen bonding). For the quantification of these effects we dried to detect correlations between the diffusion coefficients in octan-1-ol and the near infrared (NIR)-spectra of the solutions. In our study we chose four aliphatic alcohols, benzene, phenol and seven substituted benzenes. By means of different methods of multivariate analysis (PCR, PLS) we tested the possibilities of the classification and prediction of diffusion coefficients using NIR-spectra. From the preliminary results and under the usual assumption that NIR spectra refer to specific solute–solvent interactions it can be concluded that these interactions also play an important role in the diffusive transport mechanism in liquid octan-1-ol.