DESCRIPTION OF VAPOR-PRESSURES OF POLYCYCLIC AROMATIC-COMPOUNDS BY GRAPH-THEORETICAL INDEXES

The vapour pressure (VP) is an important physical property of organic compounds for the description of fate and distribution of xenobiotics in the environment. This property was measured for 30 polycyclic aroma tic hydrocarbons (PAH) and formulas for VP based on molecular weight a nd topological indices, respectively, were derived using the technique of Kubinyi and as a second step by regression analysis. A formula for the 30 PAH, considered here, is given. [GRAPHICS] Therein the VP is r elated to the information theoretical index IdWmean and with a chain-c onnectivity index. More specific results are derived for three groups of PAHs. The robustness of the equations is tested by bootstrap analys is. In addition a formula is discussed, which is based on four differe nt incremental factors, a method widely used in physical organic chemi stry.