STRUCTURE-PROPERTY RELATIONSHIPS - DETERM INATION OF THE VAPOR-PRESSURE OF ALKANES AND ALCOHOLS USING MULTIFUNCTIONAL AUTOCORRELATION METHOD (MAM)

Vapour pressure was estimated for 142 alkanes and 44 alcohols by the 0 .5MAM method, using components of the autocorrelation vector. Surface S, calculated from Bondi's surface areas. Other methods (Wiener, Kier, AMP, UNIFAC, ad hoc) were compared with MAM. For alkanes, five compon ents of the Surface vector gave a good correlation (r = 0.9981 s = 0.0 45). Fewer variables gave results similar to those of the other method s, but the method of Wiener with DELTAW and DELTAP gave better results (s = 0.03). For alcohols, MAM (using two vectors: Lipophilic Surface SL and Functional Surface SF) and ad hoc were the most effective metho ds. Using more variables improved the results (r = 0.996, s = 0.11 wit h four variables and r = 0.999, s = 0.05 with seven variables). When a lkanes and alcohols were joined, only MAM and UNIFAC gave correct resu lts. Five MAM variables gave the equation logP(upsilon) = - 1.29SF0 - 0.52SF1 + 0.08SF3 - 0.31 SL0 - 0.058SL1 + 5.61 n = 186, r = 0.994, s = 0.10, F = 2,792.