Journal ArticleDOI
Absolute Rate Constants for the Addition of Methyl Radicals to Alkenes in Solution: New Evidence for Polar Interactions
Torsten Zytowski,Hanns Fischer +1 more
TLDR
In this paper, absolute rate constants for the addition of the methyl radical to 20 monosubstituted and 1, 1 disubstitized alkenes at room temperature in liquid solution were reported.Abstract:
Absolute rate constants are reported for the addition of the methyl radical to 20 monosubstituted and 1,1-disubstituted alkenes at room temperature in liquid solution. They increase with increasing exothermicity of the addition and are enhanced by strong nucleophilic polar effects for electron-deficient alkenes. This agrees with conclusions derived from earlier relative rate data but disagrees with a general insignificance of polar effects predicted by ab initio calculations.read more
Citations
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Journal ArticleDOI
Factors Controlling the Addition of Carbon‐Centered Radicals to Alkenes—An Experimental and Theoretical Perspective
Hanns Fischer,Leo Radom +1 more
TL;DR: The analysis leads to a partial revision of the previous qualitative rules, and it more clearly exhibits the interplay of the reaction enthalpy effects, polar charge-transfer contributions, and steric substituent effects on the reaction energy barrier.
Journal ArticleDOI
Cyclizations of Alkynes: Revisiting Baldwin’s Rules for Ring Closure
Kerry Gilmore,Igor V. Alabugin +1 more
Journal ArticleDOI
Versatile Enantioselective Synthesis of Functionalized Lactones via Copper-Catalyzed Radical Oxyfunctionalization of Alkenes.
Rong Zhu,Stephen L. Buchwald +1 more
TL;DR: A versatile method for the rapid synthesis of diverse enantiomerically enriched lactones has been developed based on Cu-catalyzed enantioselective radical oxyfunctionalization of alkenes, which provides straightforward access to a wide range of useful chiral lactone building blocks containing tetrasubstituted stereogenic centers.
Journal ArticleDOI
The mechanism of the propagation step in free-radical copolymerisation
TL;DR: In this article, it is concluded that the "explicit" or complete penultimate model should be regarded as the base model for the majority of copolymerisation reactions, based on the weight of evidence from the cumulative findings of a diverse range of studies, viz. the determination of average propagation rate coefficients in co and terpolymerisation systems, moderated copolymisation studies, solvent effects studies, ESR studies of model-radicals, and both experimental and theoretical studies of gamma-substituent effects in small-radical addition reactions.
Journal ArticleDOI
The nature of the chain-length dependence of the propagation rate coefficient and its effect on the kinetics of free-radical polymerization. 1. Small-molecule studies
TL;DR: In this paper, the authors summarize and analyze the currently available small-molecule data, both experimental and theoretical, that is relevant to chain-length-dependent propagation in free-radical polymerization (FRP).
References
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Journal ArticleDOI
Evaluated Kinetic Data for Combustion Modelling
Donald L. Baulch,Carlos J. Cobos,Richard A. Cox,C. Esser,P. Frank,Th. Just,J. A. Kerr,Michael J. Pilling,Jürgen Troe,Raymond W. Walker,J. Warnatz +10 more
TL;DR: In this paper, the authors present a compilation of critically evaluated kinetic data on elementary homogeneous gas phase chemical reactions for use in modelling combustion processes Data sheets are presented for some 196 reactions each data sheet sets out relevant thermodynamic data, rate coefficient measurements, an assessment of the reliability of the data, references and recommended rate parameters Tables summarizing the preferred rate data are also given
Journal ArticleDOI
Solvent effects on the competitive .beta.-scission and hydrogen atom abstraction reactions of the cumyloxyl radical. Resolution of a long-standing problem
TL;DR: In this paper, laser flash photolysis (LFP) techniques with detection in the infrared and in UV-visible regions of the spectrum have been used in combination with detailed product studies to assess solvent effects on the hydrogen abstraction and β-scission reactions of cumyloxyl radicals.
Journal ArticleDOI
Pulse radiolysis of aqueous solutions of methyl iodide and methyl bromide. The reactions of iodine atoms and methyl radicals in water
Journal ArticleDOI
Absolute rate constants for some reactions of perfluoro-n-alkyl radicals in solution
TL;DR: In this article, the absolute rate constants have been measured at 298±2 K for some reactions of C 2 F 5., n-C 3 F 7., N-C 7 F 15., and N -C 8 F 17.
Journal ArticleDOI
Comparison of the addition of ch3., ch2oh., and ch2cn. radicals to substituted alkenes : a theoretical study of the reaction mechanism
TL;DR: In this article, high-level ab initio calculations at the QCISD/6-311G∗∗ + ZPVE level have been carried out to study the addition reactions of CH, CHOH∗, and CHCN∗ radicals to the substituted alkenes CH=CHX (X = H, NH, F, CI, CHO, and CN) and the results analyzed with the aid of the curve-crossing model.
Related Papers (5)
Comparison of the addition of ch3., ch2oh., and ch2cn. radicals to substituted alkenes : a theoretical study of the reaction mechanism
Separation of polar and steric effects on absolute rate constants and arrhenius parameters for the reaction of tert‐butyl radicals with alkenes
K. Münger,Hanns Fischer +1 more