ON THE THREE-DIMENSIONAL WIENER NUMBER

A novel approach to the Wiener number is described. It is based on the distance matrix in which topographic (geometric) distances rather than topological (graph-theoretical) distances are the input entries. The Wiener number defined in this novel way is thus the representative of 3D (topographic) molecular descriptors. This novel Wiener number is tested in quantitative structure-property relationships (QSPR) with enthalpy functions of the lower alkanes. Its performance is compared to that of the traditional 2D Wiener number. The statistical analysis favours the QSPR models with the 3D Wiener numbers over the related QSPR models with the 2D Wiener numbers. Among the considered models with the 3D Wiener numbers, the best agreement with experimental enthalpy functions is obtained with the logarithmic QSPR model.