Extended Wiener indices. A new set of descriptors for quantitative structure-property studies

Higher order analogues of the Wiener number are defined, providing rather precise regression models for a number of physico-chemical properties of alkanes, which certainly are much better than the analogous models based solely on the Wiener number. The new structure descriptors are defined on the basis of the Wiener-Hosoya polynomial H-G(x): the kth extended Wiener index W-k is equal to the kth derivative of H-G(x), evaluated at x = 1, in which case W-1 is just the original Wiener number.