Pregled bibliografske jedinice broj: 166081
Predicting abiotic transformation rates: QSARs vs. direct calculation
Predicting abiotic transformation rates: QSARs vs. direct calculation // SETAC Europe 13th Annual Meeting
Hamburg, Njemačka, 2003. (pozvano predavanje, nije recenziran, sažetak, znanstveni)
CROSBI ID: 166081 Za ispravke kontaktirajte CROSBI podršku putem web obrasca
Naslov
Predicting abiotic transformation rates: QSARs vs. direct calculation
Autori
Sabljić, Aleksandar
Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni
Skup
SETAC Europe 13th Annual Meeting
Mjesto i datum
Hamburg, Njemačka, 27.04.2003. - 01.05.2003
Vrsta sudjelovanja
Pozvano predavanje
Vrsta recenzije
Nije recenziran
Ključne riječi
troposphere; hydroxyl radical; halogenated hydrocarbons
Sažetak
The reaction with the hydroxyl (OH) radical is the major chemical loss process for the organic compounds emitted into the troposphere. This removal process is critical for the ozone pollution in urban as well as rural areas, stratospheric ozone depletion, long range transport of chemicals, acid deposition, and global climate change. There are two general QSAR models for estimating tropospheric degradation of organic compounds, Atkinson’ s group contribution method (E.S.C. Kwok, R. Atkinson. Atmos. Environ. 29, 1685, 1995) and the MOOH method (A. Klamt. Chemosphere 26, 1273, 1993). An extensive evaluation has shown that Atkinson’ s method is far more accurate and consequently should be used as a method of choice. However, Atkinson’ s method should not be used to estimate tropospheric degradation of haloalkenes and haloalkanes with CX<sub>3</sub> (X=F, Cl, Br) groups, perhalogenated compounds and ethers (especially polyethers, cycloethers and halogenated ethers). Its application is also discouraged for chemical classes not used in its development. A viable alternative to Atkinson’ s and MOOH methods for estimating tropospheric degradation and tropospheric half-lifes of organic chemicals is the direct calculation of their reaction rate constants with hydroxyl radical. The dramatic developments in computing technology enabled the calculations of the energy profiles of gas-phase reactions to be performed almost routinely (S. Sekusak, K.R. Liedl, B.M. Rode, A. Sabljic, J. Phys. Chem. A 101, 4245, 1997). Recently, an affordable methodology was developed for calculating reaction rate constants at low computational cost. It is based on reliable semiempirical potential energy surfaces and the computed rate constants differ from experiment at most by a factor of 2 (S. Sekusak, A. Sabljic. J. Phys. Chem. A 105, 1968, 2001). This approach is particularly suitable for estimating tropospheric degradation of haloalkenes and haloalkanes with CX<sub>3</sub> (X=F, Cl, Br) groups.
Izvorni jezik
Engleski
Znanstvena područja
Kemija
POVEZANOST RADA
