Alkenes nitrogen dioxide

Ozone ALkenes, aromatic compounds, bromine, diethyl ether, ethylene, HBr, HI, nitric oxide, nitrogen dioxide, rubber, stibine... 

Much evidence has been accumulated that the ozone-olefin reaction has a predominant role in aerosol formation from alkenes, cyclic olefins, diolefins, and other unsaturated compounds. Free radicals are formed in the reaction and can react further, along with nitric oxide and nitrogen dioxide, either with the various intermediates or with the olefin itself (see the recent review by Pitts and Finlayson ). 

Shortly thereafter, in a classic series of papers in the early 1950 s, Arie Haagen-Smit and co-workers reported that these plant damage symptoms observed outdoors in ambient air could be duplicated in the laboratory by irradiating plants with sunlight and concurrently exposing them to synthetic polluted air containing alkenes and nitrogen dioxide ... 

Nitrogen dioxide, Alkenes, 4720 Nitrogen oxide, Dienes, Oxygen, 4719... 

Pokholok T. V., Pariiskii G. B. Formation of spin-labeled maeromoleeules in reactions of elastomers with nitrogen dioxide. Polymer Science, Ser A 1997 39 (7) 765-71. Giamalva D. H., Kenion G. B., Chureh D. F., Pryor W. A. Rates and mechanisms of reactionof nitrogen dioxide with alkenes in solution. J. Am. Chem. Soc. 1987 (109) 7059-63. 

Park J. S. B., Walton J. C. Reactions of nitric oxide and nitrogen dioxide with functionalised alkenes and dienes. J. Chem. Soc., Perkin Trans. 2 1997 2579-83. 

The reaction is akin to the Ritter reaction, with activation achieved by nitration, rather than proton-ation, and the products accordingly retain the nitro group. Additions to 1-phenylcyclohexene (59%) and to franr-stilbene (72%) are stereospecific (trans) cfr-stilbene gives the expected tfireo product (39%) plus some erythro (6%). Reactions of nitrogen dioxide with alkenes are very complex and rarely use-ful. A recent mechanistic paper gives many key references. " Addition of NjOs is occasionally usefiil, as with dicyclopentadiene (Scheme 49). ... 

The reaction of alkenes with nitric oxide (NO), a mixture of nitric oxide and oxygen, or dinitrogen trioxide leads to /i-nitroso nitro compounds ( / -nitrosites or pseudo-nitrosites), which can convert to nitroso dimers79. Nitroalkenes are common byproducts in these reactions. The formation of /i-nitroso nitro compounds in the reaction between alkenes and nitric oxide is explained by the presence of nitrogen dioxide and dinitrogen trioxide in the nitric oxide. The reaction may be initiated by the attack of the N02 radical on the alkene to give a /i-nitroalkyl radical which then couples with nitric oxide. 

The reactivity of alkanes and cycloalkanes are very low. Alkenes and alkynes containing double and triple bonds are reactive. The addition reactions follow Markovnikov rule. Conjugated dienes undergo Diels-Alder reactions. The substances that may react violently with unsaturated hydrocarbons are halogens, strong oxidizers, and nitrogen dioxide. Alkynes may form acetylides with certain metals. 

Laser PAS has been used to monitor air samples. Minimum detectable concentrations of gaseous pollutants are often in the parts per billion (ppb) or sub-ppb range depending on the molecular absorption cross section and on possible absorption interferences. Most studies have been devoted to investigations on collected air samples of different origin. A CO laser-based PAS has been used for analysis of vehicular exhausts. A number of compounds such as nitric oxide, nitrogen dioxide, H2O vapor, and other volatile organic compounds such as alkenes, aromatic hydrocarbons, and aldehydes have been reported. A mobile PAS system has been developed for analysis in the field. 

The photoelimination of carbon dioxide from esters and lactones is a process that has been the subject of detailed investigations. Discussion here is limited to nitrogen containing systems. 3,4-Diphenylsydnone (464), on irradiation in benzene, is converted via the nitrile imine 465 into 2,4,5-triphenyl-1,2,3-triazole (466)388 initial bond formation between N-2 and C-4 followed by loss of carbon dioxide to give the diazirine 467 is proposed to account for the formation of the nitrile imine. Nitrile imines generated in this way have been trapped with alkenes and alkynes to give pyrazoles389... 

---