The unimolecular decomposition of vibrationally excited 1‐deuterio‐1,1,2‐trifluoroethane

The photolysis of carbon tetrachloride in the presence of a number of alkanes has been investigated in the gas phase. The products obtained from the photolysis experiments were those expected from a chain reaction in which trichloromethyl radicals abstract hydrogen atoms from the alkane. The data have been used to determine Arrhenius parameters for hydrogen abstraction from the series of alkanes CH4, CzH6, CzH8, and i-C4H1O by trichloromethyl radicals, ( 4 )

“…Chemically activated chlorinated hydrocarbon molecules formed in reaction (6c) by combination of trichloromethyl and alkyl radicals might be expected to eliminate HCl [8],…”

Section: Resultsmentioning

confidence: 99%

Photolysis of carbon tetrachloride in the presence of alkanes

Matheson¹,

Tedder²,

Sidebottom³

1982

“…The facile reaction between methyl radicals and HCl leads to enhanced methane formation in the chain sequence (8) and (9). The data for the two chlorofluoroethanes studied are consistent with a mechanism analogous to the one presented above.…”

Section: Chlorine Atom Abstraction From Chlorofluoroalkanes By Methylmentioning

confidence: 99%

Reaction of methyl radicals with haloalkanes

Sidebottom

Treacy

1984

“…The experiments of Follmer and Pritchard [3] consisted of cophotolysis of mixtures of 1,3-difluoroacetone and 1,1,3,3-tetrafluoroacetone-d2 over a wide range of pressures. The radical combination reaction of interest is These vibrationally excited molecules (denoted by an asterisk) may eliminate HF or DF by four distinct channels or be collisionally stabilized.…”

Section: Chzfcdf2 Systemmentioning

confidence: 99%

“…The three-centered (aa) elimination of D X or H X has been observed from chemically activated CD3CHF2 [ 11, CHzClCDCl2 [2], and CHzFCDFz [3] and from shock heated CF&HzCl [4] and CF3CHC12 [5]. The aa process becomes competitive with the more common four-centered (ap) channel if the threshold energy for the aa channel is lowered by 1,l-dihalogen substitution or if the a@ threshold is elevated by some means.…”

Section: Introductionmentioning

confidence: 98%

“…Follmer and Pritchard [3] recently measured the pressure dependence of the cis-and trans-l,2-difluoroethylene yield formed by act elimination from chemically activated 1,1,2-trifluoroethane-l-dl. In the present work the analysis used for the trichloroethane [2] is applied to the data of Follmer and Pritchard in order to determine the vibrational energy distribution of the 1,2-difluoroethylene.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Energy disposal in the three‐centered elimination of df from 1,1,2‐trifluoroethane‐1‐d₁

Holmes

Setser

Pritchard

1976

Self Cite

The chemical activation data for three-and four-centered hydrogen fluoride elimination from CHtFCDFZ have been analyzed to assign the energy released to the olefin fragment in the three-centered process and to estimate the threshold energies for elimination channels. Based upon the cis-trans isomerization rates of CHF=CHF, 78% of the total available energy was released to the olefin fragment for the cra channel. The analysis suggests the existence of an appreciable barrier (-10 kcal/mole) for the reverse reaction, addition of the CHZFCF carbene to DF. The threshold energies for aa, a@, and @a elimination from 1, I ,2-trifluoroethane-1 -dl were assigned as 71, 68, and 68 kcal/mole, respectively. Analysis of the chemical activation data for 1,1,2,2,-tetrafluoroethane, without distinguishing between the three-and four-centered elimination channels, suggests a threshold energy of -75 kcai/mole.