title: Quantitative relationship between rate constants and molecular structure descriptors for the gas phase hydrogen abstraction reactions.
abstract: The abstraction of hydrogen by general radicals has a wide role in environmental and also in technological processes because it results in reactive free radicals that play a vital role in atmospheric chemistry and also in biochemical processes. In addition to experimental studies, the theoretical modelling of this elementary reaction has been important for understanding and predicting respective rate constants. In this paper, molecular descriptors in the context of a QSAR approach are used to codify the relationship between molecular structure and rate constants. Unique experimental data is collected from the literature for the reaction R(i)• + R(j)H → R(i)H + R(j)•, where R(i)• = H• and R(j)• are diverse radicals. The four-parameter QSAR model (n = 34, r(2) = 0.81, r(2)(CV) = 0.74, r(2)(scr) = 0.12, s(2) = 0.19) is presented for the bimolecular rate constants, accompanied with model diagnostics and analysis of descriptors in the model.
authors.affiliation: Institute of Chemistry, University of Tartu, Tartu, Estonia.
authors.forename: Maikki
authors.initials: M
authors.lastname: Moosus
authors.forename: Rein
authors.initials: R
authors.lastname: Hiob
authors.forename: Uko
authors.initials: U
authors.lastname: Maran
mesh_terms: D003198:Computer Simulation; D005609:Free Radicals / Q000737:chemistry* / Q000378:metabolism*; D005740:Gases; D006859:Hydrogen / Q000737:chemistry* / Q000378:metabolism*; D015394:Molecular Structure; D021281:Quantitative Structure-Activity Relationship; D013358:Subject Headings
chemical_list: D005609:Free Radicals; D005740:Gases; D006859:Hydrogen