ESTIMATION OF LIQUID-VAPOR PRESSURES FOR LOW-VOLATILITY ENVIRONMENTALCHEMICALS

Two structural descriptors were chosen as possible model descriptors f or predicting subcooled-liquid vapor pressures of polychlorinated biph enyls (PCBs), chlorophenols (CPs), chlorobenzenes (CBs) and alkylpheno ls and predictive power of the two descriptors are discussed. The Char acteristic Root Index (CRT) and third order cluster-type molecular con nectivity index ((3) chi(c)) were calculated exclusively on the basis of information readily available for all chemicals. To apply the regre ssion model to a wide range of chemicals multiple linear regression ha s been tried, however, collinearity was observed between the two struc tural descriptors. Subcooled-liqiud vapor pressures obtained by using the best correlative equation with the CRI for 54 PCB congeners, all c hlorophenols and chlorobenzenes and several alkylphenols have been rep orted. (C) 1997 Elsevier Science Ltd.