Nitroxy 1 compounds

The compd has a brisance of 5.4g of sand crushed (TNT 48.0), an expln temp of 275° in 4 secs, impact sensy of 18,r using a 2-kg wt and 34m using a 500g wt and a thermal stab at 100° of evapn with no sign of decompn Refs 1) Beil, not found 2) JJ. Picard et al, Investigation of Some New Fluoro-Nitroxy Compounds , FRL Proplnt Section Rept 9 (1960) 3) Y J. Carignan, Study of the... 

Nitroxides s. N-Oxide radicals Nitroxy compounds s. Bis-(trifluoromethyl)nitroxy derivatives Nitryl fluoride... 

Both compounds A and B are stable at room temperature. Cleavage of the Ge—O bond in both bis(trifluoromethyl)nitroxy derivatives A and B by hydrogen chloride led to the corresponding chloro derivatives C and D (equations 23 and 24). C and D are stable at —20 °C but, on standing for two days, both compounds polymerized. 

To protect the hydroxyl groups of the compound (VII) or (XIII) by acetylation Wright cooled a solution after nitrolysis to — 55°C and then added acetic anhydride at a temperature below — 25°C. Apart from cyclonite he isolated l-acetoxy-7-nitroxy-2,4,6-trinitro-2,4,6-triazaheptane (XIV). The addition of the solution from nitrolysis to acetic anhydride gave a diacetyl derivative 1,7-diacetoxy-2,4,6-trinitro-2,4,6-triazaheptane (XV) ... 

The O-nitro group (the nitroxy group) gives an absorption band of about 270 va.fi, in the ultra-violet region, i.e. a band similar to that of the C-nitro group. A relatively small amount of work has been done on the ultra-violet absorption spectra of nitric acid esters but it has been established that in esters containing no other chromophoric groups absorption is extremely low (e = 10-20) even lower than in case of aliphatic nitro compounds. 

This nitroxyperoxy radical can react with N02 to form a thermally unstable nitroxyperoxynitrate compound react with itself to form a nitrox-yalkoxy radical, hydroxy nitrate, and nitroxy-aldehyde/ketone or react with NO to form a nitroxyalkoxy radical or dinitrate. The nitroxyalkoxy radical can decompose to form an aldehyde/ketone and NOz, or can react with Oz to form a nitroxy aldehyde/ketone. 

Attack of NO3 on isoprene apparently proceeds in much the same manner, but there is considerable controversy about the precise reaction pathway because of the variety of peroxy radicals that can be formed. The products, such as 4-nitroxy-2-methyl-l-butan-3-one and methacrolein, are consistent with the initial addition of NO3 to the terminal carbon atoms to form nitro-oxy-peroxy radicals in the presence of oxygen apparently the NO3 adds preferentially to position 1 (Fig. 12). 3-methyl-4-nitroxy-2-butenal was found as the main product in these experiments. The nitro-oxy-peroxy radicals can react with NO2, in the presence of O2, to yield thermally unstable nitroxy-peroxynitrate compounds. One particularly important feature of the addition of NO3 is the extent to which the initial adduct, which might eliminate NO2 to form an epoxide, is actually converted to the nitro-oxy-peroxy radicals in the atmosphere. 

For the two investigated compounds with the chlorine atom substituted next to the double bond, the intensity of the nitroperoxy bands passed through a maximum while the nitroxy bands continued to increase during the course of the experiments. A carbonyl band at approximately 1750 cm was seen at the same time. This indicates that either a carbonyl nitrate compound or a nitrate and a carbonyl compound were formed through decomposition of the nitroperoxy nitrate intermediate. Small amounts of acetaldehyde and chloroacetaldehyde were found among the products formed from the reaction with l-chloro-2-butene. In the reaction with 3-chloro-l-butene, significant amounts of formaldehyde were formed. 

Because of their versatility and favourable properties, in addition to their relative nontoxicity in both in vitro and in vivo systems (Swartz et al. 1995, Damiani et al. 2000), it is likely that nitroxi-des will find increasing use in viable biological systems. The results obtained overall by Damiani et al. (2000) in an in vitro study of oxidative DNA damage and the effect of nitroxides shed more light on the antioxidant activity of this particular class of compounds and lead to a better understanding of the full exploitation of these powerful tools. 

The in situ approach leads to the formation of multiple nitroxide initiating species and there is not perfect stoicheometry between the initiating and mediating species. With the presynthesis approach, a pure compound can be used to initiate polymerization which should lead to cleaner chemistry. However, it has been believed that excess nitroxy radicals is important to achieve narrow polydis-persity and good end-group purity (249). 

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