Hydrogen Atom Bond Increments for Calculation of Thermodynamic Properties of Hydrocarbon Radical Species

1995 ◽  
Vol 99 (39) ◽  
pp. 14514-14527 ◽  
Author(s):  
Tsan H. Lay ◽  
Joseph W. Bozzelli ◽  
Anthony M. Dean ◽  
Edward R. Ritter
Keyword(s):  
Hydrogen Atom ◽  
Thermodynamic Properties ◽  
Hydrocarbon Radical ◽  
Radical Species ◽  
Atom Bond

Predictive Theory for Hydrogen Atom−Hydrocarbon Radical Association Kinetics

2005 ◽  
Vol 109 (21) ◽  
pp. 4646-4656 ◽  
Author(s):  
Lawrence B. Harding ◽  
Yuri Georgievskii ◽  
Stephen J. Klippenstein
Keyword(s):  
Hydrogen Atom ◽  
Hydrocarbon Radical ◽  
Predictive Theory ◽  
Association Kinetics

scholarly journals Synthesis of Spirocyclic Piperidines by Radical Hydroarylation

Synlett ◽  
2020 ◽  
Author(s):  
Racheal M. Spurlin ◽  
Amber L. Harris ◽  
Nathan T. Jui ◽  
Cameron J. Pratt
Keyword(s):  
Hydrogen Atom ◽  
Aryl Halide ◽  
Precious Metals ◽  
Hydrogen Atom Transfer ◽  
Atom Transfer ◽  
Aryl Radical ◽  
Radical Species ◽  
Mild Conditions

AbstractReported here are conditions for the construction of spirocyclic piperidines from linear aryl halide precursors. These conditions employ a strongly reducing organic photoredox catalyst in combination with a trialkylamine reductant to achieve formation of aryl radical species. Regioselective cyclization followed by hydrogen-atom transfer affords a range of complex spiropiperidines. This system operates efficiently under mild conditions without the need for toxic reagents or precious metals.

Properties and reactivities of nonheme iron(iv)–oxo versus iron(v)–oxo: long-range electron transfer versus hydrogen atom abstraction

2014 ◽  
Vol 16 (41) ◽  
pp. 22611-22622 ◽  
Author(s):  
Baharan Karamzadeh ◽  
Devendra Singh ◽  
Wonwoo Nam ◽  
Devesh Kumar ◽  
Sam P. de Visser
Keyword(s):  
Electron Transfer ◽  
Hydrogen Atom ◽  
Long Range ◽  
Cation Radical ◽  
Nonheme Iron ◽  
Hydrogen Atom Abstraction ◽  
Computational Studies ◽  
Radical Species ◽  
Oxo Ligand

Computational studies show that the perceived nonheme iron(v)–oxo is actually an iron(iv)–oxo ligand cation radical species.

scholarly journals Theoretical Study about the Effect of Halogen Substitution on the Reactivity of Antitumor 3-Formylchromones and Their Free Radicals

2017 ◽  
Vol 2017 ◽  
pp. 1-5
Author(s):  
Maximiliano Martínez-Cifuentes ◽  
Boris Weiss-López ◽  
Ramiro Araya-Maturana
Keyword(s):  
Free Radicals ◽  
Hydrogen Atom ◽  
Gas Phase ◽  
Theoretical Study ◽  
Computational Study ◽  
Bond Dissociation Enthalpy ◽  
Radical Species ◽  
Anticancer Compounds ◽  
Dissociation Enthalpy ◽  
Polarizable Continuum

The mandatory presence of a chlorine atom on the aromatic ring of 6-hydroxy-3-formyl angular chromones, on the respiration inhibition of mammary carcinoma mouse, is explained through a computational study of these compounds. This study analyzes the reactivity of the neutral molecules and their free radicals, in gas phase and with water solvation, incorporated by the polarizable continuum medium (PCM) approach. Electrophilic reactivities were evaluated using Fukui (f+) and Parr (P+) functions. The stabilities of radical species formed by the abstraction of a hydrogen atom from the O-H bond were evaluated by bond dissociation enthalpy (BDE) and spin density (SD) calculations. This study has potential implications for the design of chromone analogues as anticancer compounds.

1.12 Intermolecular Radical C—H Functionalization

2021 ◽  
Author(s):  
M. Bietti ◽  
F. Dénès
Keyword(s):  
Hydrogen Atom ◽  
Transition Metal ◽  
Bond Formation ◽  
Metal Catalysts ◽  
Hydrogen Atom Transfer ◽  
Transition Metal Catalysts ◽  
Radical Species ◽  
Significant Challenge ◽  
Site Selectivity ◽  
Selection Of

AbstractThe generation of carbon-centered radicals via intermolecular hydrogen-atom transfer (HAT) from C—H bonds to an abstracting species (HAT reagent) represents a significant challenge in terms of reactivity, site-selectivity and stereoselectivity. The radical species resulting from such a transfer can then engage in carbon—carbon or carbon—heteroatom bond formation, possibly through the intervention of transition-metal catalysts, leading to a variety of functionalized products. This chapter aims to provide the reader with useful guidelines to understand, predict, and design selective radical transformations based upon initial HAT from a C—H bond coupled to different radical-capture strategies. A selection of examples that illustrate different approaches to implement HAT reactions in synthetically useful procedures are presented.

scholarly journals Photoinduced 1,2-Hydro(cyanomethylation) of Alkenes with a Cyanomethylphosphonium Ylide

Synlett ◽  
2019 ◽  
Vol 30 (04) ◽  
pp. 511-514 ◽  
Author(s):  
Tomoya Miura ◽  
Daisuke Moriyama ◽  
Yuuta Funakoshi ◽  
Masahiro Murakami
Keyword(s):  
Ascorbic Acid ◽  
Double Bond ◽  
Hydrogen Atom ◽  
Visible Light ◽  
Efficient Method ◽  
Alkyl Radical ◽  
Catalytic Cycle ◽  
Iridium Complex ◽  
Radical Species ◽  
Aliphatic Nitrile

An efficient method has been developed for the 1,2-hydro(cyanomethylation) of alkenes, in which a cyanomethyl radical species is generated from a cyanomethylphosphonium ylide by irradiation with visible light in the presence of an iridium complex, a thiol, and ascorbic acid. The cyanomethyl radical species then adds across the C=C double bond of an alkene to form an elongated alkyl radical species that accepts a hydrogen atom from the thiol to produce an elongated aliphatic nitrile. The ascorbic acid acts as the reductant to complete the catalytic cycle.

Models of Thermodynamic Properties of Prominences

1979 ◽  
Vol 44 ◽  
pp. 349-355
Author(s):  
R.W. Milkey
Keyword(s):  
Thermodynamic Properties ◽  
Mass Transport ◽  
Emission Spectrum ◽  
Thermodynamic Parameters ◽  
Working Group ◽  
Physical Processes ◽  
Theoretical Concepts ◽  
Group 3 ◽  
Observational Techniques

The focus of discussion in Working Group 3 was on the Thermodynamic Properties as determined spectroscopically, including the observational techniques and the theoretical modeling of physical processes responsible for the emission spectrum. Recent advances in observational techniques and theoretical concepts make this discussion particularly timely. It is wise to remember that the determination of thermodynamic parameters is not an end in itself and that these are interesting chiefly for what they can tell us about the energetics and mass transport in prominences.

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