5649-95-6Relevant academic research and scientific papers
Matrix-Controlled Photochemistry of Benzene and Pyridine
Johnstone, Duncan E.,Sodeau, John R.
, p. 165 - 169 (2007/10/02)
Dewar benzene has been shown to be a primary product from the photolysis of benzene in low temperature argon matrices at 253.7 nm.This is the first observation of Dewar benzene production at this wavelength and a mechanism is proposed that involves benzene S1-S2 state mixing induced by the matrix environment.Analogous experiments on the photolysis of pyridine show that the only primary products are isomeric species derived at least in part from a triplet state of pyridine, probably T1.This is the first observation of photochemistry from the T1 state and may be the process responsible for the small values of τp and ψp in pyridine.Analysis of the IR spectral bands points to the main product being Dewar pyridine although other isomers cannot be ruled out.In contrast to the gas phase, no decomposition of pyridine was found in matrices poducing compounds such as acrylonitrile, ethyne, and hydrogen cyanide.
3,4-DIAZABENZVALENE, THE AZOALKANE PRECURSOR TO TETRAHEDRANE. SYNTHESIS AND REACTIVITY.
Kaisaki, David A.,Dougherty, Dennis A.
, p. 5263 - 5266 (2007/10/02)
The title diazene 1 has been synthesized and shown to decompose thermally to cyclobutadiene over a surprisingly small barrier.
Experiments to Synthesize a Formal Nitrile Oxide-Benzene Adduct. 1,3-Dipolar Cycloadditions to Bicyclohex-5-ene-2,3-dicarboxylic Anhydride, Dewar Benzene, and 1,4-Cyclohexadiene
Christl, Manfred,Mattauch, Brigitte
, p. 4203 - 4223 (2007/10/02)
The reaction of bicyclohex-5-ene-2,3-dicarboxylic anhydride (7) with benzonitrile oxide, 2,4,6-trimethylbenzonitrile oxide, diphenylnitrile imine, diazomethane, tetrachloro-o-quinone, and tetrachlorothiophene 1,1-dioxide furnished the Δ2-isoxazolines 8a, 8b, the Δ2-pyrazoline 8c, the Δ1-pyrazoline 10d, the α-diketone 11, and the tetrachloro-1,3-cyclohexadiene derivative 12, respectively. - Dewar benzene (16) was prepared via the urazole 13, obtained from benzvalene by the addition of 4-methyl-4H-1,2,4-triazole-3,5-dione, and the azo compound 17, from which nitrogen gas eliminated by photolysis.The 1:1 adducts 6a, 6b, 20, and 21 as well as the 1:2 adducts 18a, 18b, 19b, 22, and 23, respectively, were formed on treatment of 16 with benzonitrile oxide, 2,4,6-trimethylbenzonitrile oxide, and diazomethane.At 120 deg C the 1:1 adduct 6b decomposed to give benzene and the 1:2 adducts 18b, 19b, probably via the intermediate 1b, which was the target molecule of this investigation.If the thermolysis was carried out in the presence of dimethyl fumarate, 18b, 19b were no longer observed and the dimethyl Δ2-isoxazoline-3,4-dicarboxylate 24 was obtained instead. - 1,4-Cyclohexadiene reacted with benzonitrile oxide and 2,4,6-trimethylbenzonitrile oxide to provide the 1:1 adducts 25 and the 1:2 adducts 26 - 28.The thermal decomposition of 25b resulted in the formation of mesitylphenylketimine (31).A 3:1 mixture of the dibromides 32 and 33 was obtained on addition of bromine to 25a.Elimination of hydrogen bromide from 32 was effected by diazabicycloundecane with benzene and diphenylfuroxan (35) being the products and the formal benzene adduct 1a the most likely intermediate.Compound 32 was tr ansformed into the spiran 36 by using the stronger base potassium tert-butoxide.
