title: Hydrogen Abstraction Reactions from Phenolic Compounds by Peroxyl Radicals: Multireference Character and Density Functional Theory Rate Constants.
abstract: An assessment of multireference character in transition states is considered to be an important component in establishing the expected reliability of various electronic structure methods. In the present work, the multireference characters of the transition states and the forming and breaking of bonds for a large set of hydrogen abstraction reactions from phenolic compounds by peroxyl radicals have been analyzed using the T1, M, B1, and GB1 diagnostics. The extent of multireference character depends on the system and on the conditions under which the reaction takes place, and some systematic trends are observed. In particular, the multireference character is found to be reduced by solvation, the size of the phenolic compound, and deprotonation in aqueous solution. However, the deviations of calculated rate constants from experimental ones are not correlated with the extent of multireference character. The performance of single-determinant density functional theory was investigated for the kinetics of these reactions by comparing calculated rate constants to experimental data; the results from these analyses showed that the M05 functional performs well for the task at hand.
authors.affiliation: Departamento de Química, Universidad Autónoma Metropolitana-Iztapalapa , San Rafael Atlixco 186, Col. Vicentina. Iztapalapa, 09340 México D.F., México.
authors.forename: Annia
authors.initials: A
authors.lastname: Galano
authors.affiliation: Departamento de Física y Química Teórica, Facultad de Química, Universidad Nacional Autónoma de México , México D.F. 04510, México.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Muñoz-Rugeles
authors.affiliation: Departamento de Física y Química Teórica, Facultad de Química, Universidad Nacional Autónoma de México , México D.F. 04510, México.
authors.forename: Juan Raul
authors.initials: JR
authors.lastname: Alvarez-Idaboy
authors.affiliation: Department of Chemistry, Chemical Theory Center, and Supercomputing Institute, University of Minnesota , Minneapolis, Minnesota 55455-0431, United States.
authors.forename: Junwei Lucas
authors.initials: JL
authors.lastname: Bao
authors.affiliation: Department of Chemistry, Chemical Theory Center, and Supercomputing Institute, University of Minnesota , Minneapolis, Minnesota 55455-0431, United States.
authors.forename: Donald G
authors.initials: DG
authors.lastname: Truhlar