Indirect photolysis of organic compounds: prediction of OH reaction rate constants through molecular orbital calculations.

Autor: Böhnhardt A; UFZ Helmholtz Centre for Environmental Research., Kühne R, Ebert RU, Schüürmann G
Jazyk: angličtina
Zdroj: The journal of physical chemistry. A [J Phys Chem A] 2008 Nov 13; Vol. 112 (45), pp. 11391-9. Date of Electronic Publication: 2008 Oct 17.
DOI: 10.1021/jp8052218
Abstrakt: The MOOH approach is a perturbational molecular orbital method to predict rate constants of indirect photolysis of organic compounds through reaction with OH radicals. It employs the semiempirical AM1 scheme as the underlying quantum chemical model. The original method introduced by Klamt has been reparametrized using an up-to-date set of 675 compounds with experimental rate constants and outperforms the prominent Atkinson increment scheme for this training set as well as for an extended set of 805 compounds, yielding an overall root-mean-square error of 0.32 log units. The discussion includes detailed comparative analyses of the model performances for individual compound classes. The present model calibration refers mainly to monofunctional compounds but performs already reasonably well for multifunctional compounds. For predictive applications, both the Atkinson scheme and the alternative, independent AM1-MOOH model can be used as components of a consensus modeling approach, arriving at increased confidence in cases where the different models agree.
Databáze: MEDLINE