doi:10.1016/j.atmosenv.2003.09.055
Copyright © 2003 Elsevier Ltd. All rights reserved.
Molecular polarizability as a single-parameter predictor of vapour pressures and octanol–air partitioning coefficients of non-polar compounds: a priori approach and results
M. Staikovaa, F. Waniab and D. J. Donaldson
,
, a, b
a Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ont., Canada M5S 3H6
b Department of Physical and Environmental Sciences, University of Toronto at Scarborough, 1265 Military Trail, Toronto, Ont., Canada M1C 1A4
Received 27 May 2003;
accepted 17 September 2003. ;
Available online 22 October 2003.
References and further reading may be available for this article. To view references and further reading you must
purchase this article.
Abstract
We present a one-parameter quantitative structure–property relationship (QSPR) which relates the vapour pressures, PL, and octanol–air partition coefficients, KOA, of a series of chlorinated organic compounds to their molecular polarizabilities. Polarizabilities, dipole moments and quadrupole moments were calculated for the complete set of chlorobenzenes, the mono-, di-, and tri-substituted chloronaphthalenes, the mono-, di-, tri-, and tetra-substituted chlorobiphenyls, and the chloroalkanes with one, two and three carbons using Density Functional Theory methods at the B3LYP/6-311G(d, p) level. Only the molecular polarizability was found to be significantly correlated with logPL and logKOA. The regression coefficients for plots of experimental values of logPL and logKOA as a function of molecular polarizability are approximately 0.98, indicating that non-specific intermolecular forces are dominant in governing the gas–condensed phase transition in these molecules. The predictive ability of the single-parameter QSPR is suggested by near-identical values of the residual sum of squares and PRESS parameters. We suggest that the QSPRs derived here could be used more generally.
Author Keywords: QSPRs; Octanol–air partitioning; Vapour pressure; Chlorinated aromatics
Fig. 1. Plots of (a) logPL (PL in Pa) and (b) logKOA against the average molecular polarizabilities (α in Å3) for all 159 compounds calculated here. The different symbols represent different compound classes. CCl4, C3H3Cl3 and C12H10, three compounds with similar mass but very different partitioning behaviours, are indicated by arrows. The best-fit straight lines are shown. Legend: circles, CBzs; squares, PCNs; triangles, PCBs; diamonds, C1 alkanes; octagons, C2 alkanes; and crosses, C3 alkanes.
Fig. 2. Calculated (using
Eq. (1), given in
Table 2) vs. experimental values of: (a) log(
PL) (
PL in Pa) and (b) log
KOA. The best-fit lines are shown. For (a) the slope is 0.92 and the intercept is 0.079, with
r2=0.96; for (b) the slope is 0.99 and the intercept is 0.048, with
r2=0.97.
Fig. 3. Similar to
Fig. 1, but showing plots of (a) log
PL (
PL in Pa) and (b) log
KOA against the dipole moments (in Debye) calculated for the chlorinated alkanes.
Fig. 4. Similar to
Fig. 1, but showing plots of (a) log
PL (
PL in Pa) and (b) log
KOA against the quadrupole moments (in Debye Å) calculated for the chlorinated benzenes.
Fig. 5. (a) Correlation of log
PL for CBzs against the main polarizability α
m and its Cartesian components α
zz and α
xy (see text for details).
PL is expressed in Pa, α is given in Å
3. (b) Correlation of log
KOA for CBzs against the average polarizability α
m and its Cartesian components α
zz and α
xy (see text for details). α is given in Å
3.
Table 1. Calculated polarizabilities and experimental partitioning parameters

Table 2. Results of significant regressions
