A Simple QSPR Model for Predicting Soil Sorption Coefficients of Polar and Nonpolar Organic Compounds from Molecular Formula

2003 ◽  
Vol 43 (6) ◽  
pp. 1928-1932 ◽  
Author(s):  
Eduardo J. Delgado ◽  
Joel B. Alderete ◽  
Gonzalo A. Jaña
Keyword(s):  
Organic Compounds ◽  
Molecular Formula ◽  
Soil Sorption ◽  
Qspr Model ◽  
Nonpolar Organic

scholarly journals Developing a Support Vector Machine Based QSPR Model to PredictGas-to-Benzene Solvation Enthalpy of Organic Compounds

2017 ◽  
Vol 33 (5) ◽  
pp. 918-926
Author(s):  
Hassan GOLMOHAMMADI ◽  
◽  
Zahra DASHTBOZORGI ◽  
Sajad KHOOSHECHIN ◽  
Keyword(s):  
Support Vector Machine ◽  
Organic Compounds ◽  
Support Vector ◽  
Qspr Model ◽  
Solvation Enthalpy

The Hydroxyl Radical and Its Role in Ozone Formation

2015 ◽  
Author(s):  
Jack G. Calvert ◽  
John J. Orlando ◽  
William R. Stockwell ◽  
Timothy J. Wallington
Keyword(s):  
Water Molecule ◽  
Organic Compounds ◽  
Complex Mixture ◽  
Peroxy Radical ◽  
Molecular Formula ◽  
Ozone Formation ◽  
Alkoxy Radical ◽  
Chain Reactions ◽  
Low Concentrations ◽  
Ho2 Radical

Although the HO radical is present in the sunlight-irradiated troposphere at very low concentrations, only about 106 molecules cm−3, it is the most important trace component in our atmosphere. It is a highly reactive transient species and is responsible for initiating the oxidation of the majority of organic compounds in the troposphere. It initiates the chain reactions that produce ozone. All the saturated, H-atom containing molecules react with HO through abstraction of an H atom. In the case of the simplest alkane, methane, reaction (1) leads to the formation of a water molecule and an alkyl (CH3) radical: . . . HO + CH4 → H2O + CH3 (1) . . . The CH3 radical released into the oxygen-rich atmosphere quickly adds O2 to give the methyl peroxy radical in reaction (2), which in NO-containing atmospheres can react to form NO2, and an alkoxy radical, CH3O, in reaction (3). In turn, this radical reacts with O2 to give an HO2 radical and a molecule of formaldehyde in (4). An HO radical can be regenerated as the HO2 molecule oxidizes NO to NO2 in (5), and the chain of events, reactions (1) through (5), leads to ozone generation through the photolysis of the NO2 molecule in reactions (6) and (7): . . . CH3 + O2 → CH3O2 (2) . . . . . . CH3O2 + NO → CH3O + NO2 (3) . . . . . . CH3O + O2 → HO2 + CH2O (4) . . . HO2 + NO → HO + NO2 (5) . . . . . . NO2 + hν → O + NO (6) . . . . . . O + O2 (+ M) → O3 (+ M) (7) . . . Methane is the least reactive of the alkanes with HO. Urban atmospheres contain a complex mixture of the more reactive larger alkanes (RH). The number of different possible geometric isomers and stereoisomers of the alkanes that can be formed by association of C and H atoms is astounding (Calvert et al., 2008). For example, there are more than a thousand structurally different molecules of molecular formula C12H26, more than a million C20H22, more than a billion of formula C25H52, and more than a trillion possible different isomers of molecular formula C31H64.

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