Absolute Rates of Intermolecular Carbon−Hydrogen Abstraction Reactions by Fluorinated Radicals

Shtarev, Alexander B.; Tian, Feng; Dolbier, William R.; Smart, Bruce E.

doi:10.1021/ja990521q

Cited by 40 publications

(42 citation statements)

References 41 publications

(51 reference statements)

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“…The synthesis of mono-deuterated DME has already been reported by Shtarev et al (1999) and has been modified as follows. Lithium aluminum deuteride (420 mg, 10 mol) and tetraglyme (20 mL) were introduced into a 100 mL two-necked flask equipped with a stirring bar, a stopcock, and a septum.…”

Section: Preparation Of Mono-deuterated Dimethyl Ethermentioning

confidence: 99%

Mono-deuterated dimethyl ether: laboratory spectrum up to 1 THz

Richard

Margulès

Caux

et al. 2013

A&A

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Context. Dimethyl ether is one of the most abundant complex organic molecules (COMs) in star-forming regions. Like other COMs, its formation process is not yet clearly established, but the relative abundances of its deuterated isotopomers may provide crucial hints in studying its chemistry and tracing the source history. The mono-deuterated species (CH 2 DOCH 3 ) is still a relatively light molecule compared to other COMs. Its spectrum is the most intense in the THz domain in the 100-150 K temperature regime, tracing the inner parts of the low-mass star-forming region. Therefore, it is necessary to measure and assign its transitions in this range in order to be able to compute accurate predictions required by astronomical observations, in particular with the telescope operating in the submm range, such as ALMA. Aims. We present the analysis of mono-deuterated dimethyl ether in its ground-vibrational state, based on an effective Hamiltonian for an asymmetric rotor molecules with internal rotors. The analysis covers the frequency range 150-990 GHz. Methods. The laboratory rotational spectrum of this species was measured with a submillimeter spectrometer (50-990 GHz) using solid-state sources. For the astronomical detection, we used the IRAM 30 m telescope to observe a total range of 27 GHz, in 4 frequency bands from 100 GHz to 219 GHz. Results. New sets of spectroscopic parameters have been determined by a least squares fit with the ERHAM code for both conformers. These parameters have permitted the first identification in space of both mono-deuterated DME isomers via detection of twenty transitions in the solar-type protostar IRAS 16293-2422 with the IRAM 30 m telescope. The DME deuteration ratio in this source appears as high as observed for methanol and formaldehyde, two species known to play an important role in the COMs formation history.

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Section: Preparation Of Mono-deuterated Dimethyl Ethermentioning

confidence: 99%

Mono-deuterated dimethyl ether: laboratory spectrum up to 1 THz

Richard

Margulès

Caux

et al. 2013

A&A

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“…4 However, until now, little attention has been paid to the influence of solvent on these reactions. Because of their high electrophilicities and the acknowledged importance of transition state polar effects on their reactivities in both hydrogen abstraction and alkene addition reactions, 3 one would predict that the rates of such reactions of perfluoro-n-alkyl radicals would be influenced by solvent polarity.…”

Section: Introductionmentioning

confidence: 99%

Absolute Rate Constants of Alkene Addition Reactions of a Fluorinated Radical in Water

Zhang

Sheeller

et al. 2002

J. Am. Chem. Soc.

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Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n'arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. Questions? Contact the NRC Publications Archive team atPublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the first page of the publication for their contact information. NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. For the publisher's version, please access the DOI link below./ Pour consulter la version de l'éditeur, utilisez le lien DOI ci-dessous. NRC Publications Record / Notice d'Archives des publications de CNRC:http://nparc.cisti-icist.nrc-cnrc.gc.ca/eng/view/object/?id=124c64aa-fb51-4827-94c3-18efb61397d2 http://nparc.cisti-icist.nrc-cnrc.gc.ca/fra/voir/objet/?id=124c64aa-fb51-4827-94c3-18efb61397d2 Abstract: Absolute rate constants of ‚RfSO3 -radical addition to a series of water-soluble alkenes containing ionic, carboxylate substituents were measured by laser flash photolysis experiments in water. The observed rate constants were all considerably larger than those of structurally similar analogues in a nonpolar organic solvent, with rate factors of 3-9-fold being observed. It is concluded that such rate enhancements derive at least in part from stabilization of the polar transition state for addition of the electrophilic fluorinated radical to alkenes by the polar solvent water.

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“…In this study, solvents that are more environmentallybeneficial, and with potentially smaller chain transfer constants in fluoropolymer synthesis were preferred. The chain transfer constants of various common organic solvents were determined previously in presence of perfluoroalkyl radicals (19). The transition state of hydrogen abstraction by highly electrophilic perfluorinated radicals favors hydrogen on carbons adjacent to an electron donating group (19,20).…”

Section: Dot) In 40/60 a A/co 2 At 17 Mpa (Entry 4 Inmentioning

confidence: 99%

Fluoropolymer Synthesis in Carbon Dioxide-Expanded Liquids: A Practical Approach to Avoid the Use of Perfluorooctanoic Acid

DeSimone

Roberts

2009

Gas-Expanded Liquids and Near-Critical Media

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Successful polymerization of tetrafluoroethylene (TFE) in CO 2 -expanded liquids to synthesize polytetrafluoroethylene (PTFE) was demonstrated using both hydrocarbon and hydrofluorocarbon solvents. Yields were satisfactory and samples with thermal properties comparable to commercial polymer were produced. The chain transfer reaction that resulted from the use of hydrogen-containing solvents was not as severe as expected. Acetic acid was identified as a particularly promising expandable solvent. Use of this solvent lowers the pressure required for polymerization of TFE, and acetic acid is less environmentally detrimental than halogenated solvents. A wide range of solvent ratios and pressures were found to be suitable for TFE polymerization in CO 2 -expanded acetic acid. Colloidal PTFE samples were obtained in an emulsion-like polymerization run in CO 2 -expanded acetic acid. A commercially-available, conventional hydrocarbon surfactant was used in this research; the process did not require fluorinated surfactants such as perfluoro octanoic acid (PFOA) or other the specially designed surfactants for CO 2 systems.

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Absolute Rates of Intermolecular Carbon−Hydrogen Abstraction Reactions by Fluorinated Radicals

Cited by 40 publications

References 41 publications

Mono-deuterated dimethyl ether: laboratory spectrum up to 1 THz

Mono-deuterated dimethyl ether: laboratory spectrum up to 1 THz

Absolute Rate Constants of Alkene Addition Reactions of a Fluorinated Radical in Water

Fluoropolymer Synthesis in Carbon Dioxide-Expanded Liquids: A Practical Approach to Avoid the Use of Perfluorooctanoic Acid

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