Molecular Rearrangement in the Mercury-Photosensitized Reaction of Butene-1

Cvetanović, R. J.; Doyle, L. C.

doi:10.1063/1.1701371

Cited by 27 publications

(3 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Methylcyclopropane was synthesized by the mercury photosensitized reaction of butene-1. 18 The identification of C4 and Ce hydrocarbons except for the minor products (methylcyclopropane and cyclobutane) was also confirmed by direct mass spectrometric analysis of peaks eluted at 0°f rom the 300-ft stainless steel capillary column coated with 1:1 squalane-/3,d' -TDPN mixture.…”

Section: Methodsmentioning

confidence: 82%

Photolysis of liquid and solid ethylene at 184.9 nm

Hirokami¹,

Cvetanović²

1974

J. Phys. Chem.

View full text Add to dashboard Cite

Publication costs assisted by the National Research Council of CanadaLow-temperature photolysis of liquid, solid, and dissolved ethylene has been studied at 184.9 nm. The major products observed in the photolysis of liquid ethylene and of ethylene-ethane solutions at -(160 * 1)" are hydrogen and acetylene. The minor products are butene-1, n-butane, 1,3-butadiene, methylcyclopropane, cyclobutane, hexene-1, and 1,5-hexadiene. Methylcyclopropane, cyclobutane, and the greater part of butene-1 appear to result from direct addition of excited ethylene molecules to ethylene. In the photolysis of dideuterioethylene in liquid nitrogen solution at 77"K, cis-trans isomerization, H-atom scrambling, molecular decomposition into hydrogen and acetylene, and a much smaller decomposition into hydrogen atoms and vinyl radicals are observed. The photolysis of liquid and dissolved ethylene may be explained by a mechanism involving either a single or, somewhat more logically, two excited states of ethylene. The two-state mechanism is formally similar to the mechanism previously postulated for the mercury (Hg(3P1)) photosensitized reaction of ethylene. Addition of vinyl radicals (but not of ethyl radicals) to ethylene at -(160 & 1)" is observed. At this temperature the ratio k(C2H3 + CzH4)/k(H + GzI14) is 0.24. Photochemically induced intermolecular hydrogen exchange at 184.9 nm between CzH4 and C2D4 in the solid phase at 77°K is at best only a very minor process. The ratio of the free radical to the molecular decomposition of liquid ethylene photolyzed at -160" is about 0.03.

show abstract

Section: Methodsmentioning

confidence: 82%

Photolysis of liquid and solid ethylene at 184.9 nm

Hirokami¹,

Cvetanović²

1974

J. Phys. Chem.

View full text Add to dashboard Cite

show abstract

“…For combination, where the energy barrier is very low or even nonexistent, the effects of steric interaction and relative spin density at the radical reaction centers are dominant. However, as the ESR spectra of methylsubstituted ally1 radicals show that the relative spin densities do not deviate 1.39 f 0.02 * Reference [8].…”

Section: E Summary Of Radical Combination Datamentioning

confidence: 99%

Reactions of unsymmetrically substituted allyl radicals with methyl radicals

Montague

1973

Int J of Chemical Kinetics

View full text Add to dashboard Cite

The Hg(6 photosensitized decompositions of 3-methyl-1 -butene, 2-methyl-2-butene, 3,3-dimethyl-l-butene, and 2,3-dimethyl-l-butene have been used to generate l-methylallyl, 1,2-dimethylallyl, 1 ,I-dimethylallyl, and 1,1,2-trimethylallyl radicals in the gas phase at 24 f 1°C. From a study of the relative yields of the CH3 combination products, the relative reactivities of the reaction centers in each of these unsymmetrically substituted ambident radicals have been determined. The more substituted centers are found to be the less ieactive, and this is ascribed primarily to greater steric interaction at these centers during reaction. Measurement of the ratio of trans-to cis-2-pentene formed from the 1 -methylally1 radical, combined with published values for this ratio at higher temperatures, enabled the differences in entropy and heat of formation of the trans-and cis-forms of this radical to be calculated as 0.62 + 0.85 J mol-'K-' and -0.63 f 0.25 kJ mol-I, respectively, at 298K. Approximate values of the disproportionation/combination ratios for reaction of Cl13 with 1,l-dimethylallyl and 1-methylallyl have been estimated and used to compute rate constants for the recombinations of tert-butyl and isopropyl radicals that are in agreement with recently published data.

show abstract

“…They noted that photosensitization of cis-ethylene-dz yielded the asymmetric product as well as the expected trans species. A later study (2) of butene-1 again provided strong evidence that this mode of reaction is operative; methylcyclopropane was found t o be a major product within an intermediate pressure range. The nature of the H-atom shift, whether 1,2 or 1,4, was, however, not e~t a b l i s h e d .~…”

Section: Introductionmentioning

confidence: 98%