31124-35-3Relevant academic research and scientific papers
Thermal isomerization of benzocyclobutene
Chapman, Orville L.,Tsou, Uh-Po Eric,Johnson, Jeffery W.
, p. 553 - 559 (2007/10/02)
Thermolysis of benzocyclobutene 13CH2, 99percent gives styrene labeled in the β (48percent), ortho (30percent), α (14percent), meta (4percent), and para (4percent) positions.The major labels (β and ortho) are consistent with a mechanism involving interconversions of the isomeric tolylmethylenes and the methylcycloheptatrienes.This mechanism also involves interconversion of o-tolylmethylene with o-xylylene and p-tolylmethylene with p-xylylene.A minor mechanism produces 25percent of styrene.This mechanism involves cleavage of the aryl carbon to the methylene carbon bond in benzocyclobutene followed by hydrogen transfer to produce styrene.Thermolysis of p-xylylene produced from paracyclophane gives styrene (55percent), p-xylene (31percent), benzocyclobutene (4percent), benzene (4percent), and toluene (3percent).Thermolysis of metacyclophane gives styrene (18percent), p-xylene (25percent), m-xylene (3percent), benzocyclobutene (1percent), benzene (7percent), and toluene (22percent).
Kinetics of Cyclopropyl Radical Reactions. 2. Studies on the Inversion of Cyclopropyl and 1-Methylcyclopropyl Radicals and on the Kinetics of Some Addition and Abstraction Reactions of 1-Methylcyclopropyl and 1-Methoxycyclopropyl Radicals
Johnston, Linda J.,Ingold, K. U.
, p. 2343 - 2348 (2007/10/02)
Laser flash photolytic studies have shown that the 1-methylcyclopropyl radical has a reactivity similar to that of the cyclopropyl radical toward styrene, β-methylstyrene, 1,4-cyclohexadiene, CCl3Br, and n-Bu3SnH but that it is more reactive toward CCl4.Chemical trapping with CCl3Br of these two radicals stereospecifically labeled with deuterium yields rate constants for their inversion at 71 deg C of (2.1 +/- 0.8) * 1011 s-1 for c-C3H4.CH3 and ca. 1012 s-1 for c-C3H5..EPR spectra of 13C-labeled radicals confirm that they are nonplanar: a13Cα = 98 and 95.9 G for c-C3H4.CH3 and c-C3H5., respectively.The similar magnitudes of these splittings implies that there is also a similar degree of deviation from planarity.The barrier to inversion is probably ca. 3 kcal/mol for both radicals but the c-C3H5. inverts more rapidly possibly because of hydrogen tunneling. 1-Methoxycyclopropyl is less reactive toward styrene and 1,4-cyclohexadiene than the other two radicals.The EPR spectrum of this radical could not be obtained.
Dissociative ionization of aryl-substituted vinyl bromides in the gas phase: Experimental and computational evidence for the formation of stable α-arylvinyl cations both by direct means and spontaneous exothermic isomerization of unstable isomeric ions
Apeloig, Yitzhak,Franke, Wilfried,Rappoport, Zvi,Schwarz, Helmut,Stahl, Daniel
, p. 2770 - 2780 (2007/10/02)
The kinetic energy release T which accompanies the Br· loss from ionized (E)- and (Z)-β-bromostyrenes (5 and 6) in the gas phase is higher by 0.7 ± 0.03 kcal mol-1 than that from the molecular ion of α-bromostyrene (4). Together with both colli
