Hydroxyalkyl nitrate

Treves K., L. Shragina and Y. Rudich Henry s law constants of some P-, y-, and 5-hydroxyalkyl nitrates of atmospheric interest. Environ. Sci. Technol. 34 (2000)1197-1203. 

Alkyl nitrates are also formed by the reaction of AgN03 with alkyl bromides in an acetonitrile solvent. The drawback of this exchange reaction is that in most cases the yield is only about 60 to 80%. Dichloromethane extraction with solvent removal under reduced pressure has been employed to isolate the alkyl nitrates as pure reference compounds, as well as to synthesize the hydroxyalkyl nitrates from the hydroxyhalides. Direct nitration of the alkanes is achieved with 12% HNO3 in the presence of solid copper. This method is especially useful in preparing mixtures of alkyl nitrates from mixtures of the starting alkanes. 

Under relatively low NOx conditions in the atmosphere, a part of alkyl peroxy radicals, and hydroxyalkyl peroxy radicals react with HO2 to give hydroperoxy butane (pathways (f), (k)), and hydroxyhydroperoxy butane (pathway (q)). Thus, in oxidation reactions of alkane in the atmosphere, hydroperoxides, hydoxyhydor-peroxides, and hydroxyalkyl nitrate, could also be produced in addition to the normal aldehydes, ketones and alkyl nitrates. 

Hydroxyalkyl nitrates are formed during the degradation of alkanes and alkenes via different mechanisms. They are formed from both OH- and NOs-initiated oxidation of these species. The yield of their formation increases with the size of the precursor alkane. Some of the formation channels involve isomerization processes (Arey et al., 2001 Reisen et al., 2005). 

Using a relative rate method, Treves and Rudich (2(X)3) have measured rate coefficients for reactions of OH radicals with a series of C3-C6 hydroxyalkyl nitrates and two C4 unsaturated hydroxyl nitrates at atmospheric pressure and 296 2 K. Wangberg et al. (1996) have reported the rate coefficient for the OH reaction with 2-nitroxy-l-cyclopentanol also using a relative rate method. The rate coefficient values obtained in both studies are given in table Vlll-G-1. 

The OH-hydroxyalkyl nitrate reaction rate coefficient values estimated using the parameters of Kwok and Atkinson (1995) for monofiinctional alcohols and nitrates are significantly higher than those measured by Treves and Rudich (2003). This disagreement has been attributed to the opposing effects of the hydroxyl and nitrooxy groups on the reactivity. 

The only study conducted on the reaction of Cl with hydroxyalkyl nitrates is that of Treves et al. (2002) using a relative rate method at atmospheric pressure and ambient temperature. Table VIII-G-2 summarizes the available data set. The presence of the hydroxy group enhances the reactivity of hydroxyl nitrates toward Cl-atoms compared... 

Table Vlll-G-1. Rate coefficients (k, cm molecule s ) for the reaction of OH with hydroxyalkyl nitrates... 

Hydroxyalkyl nitrates are more reactive in the gas phase than alkyl nitrates and are more soluble in water. It is expected that hydroxynitrates are less-effective transporters of NO , than are the alkyl nitrates. On the other hand, the OH-initiated oxidation of hydroxyl nitrates may lead to long-lived carbonyl nitrates, which could play a role in the long-range transport of NOj. 

Arey, J., S.M. Aschmann, E.S.C. Kwok, and R. Atkinson (2001), Alkyl nitrate, hydroxyalkyl nitrate, and hydroxycarbonyl formation from the NO -air photooxidations of Cs-Cs n-alkanes, J. Phys. Chem. A, 105, 1020-1027. 

Substitution reactions on dialkyl peroxides without concurrent peroxide cleavage have been reported, eg, the nitration of dicumyl peroxide (44), and the chlorination of di-/ fZ-butyl peroxide (77). Bromination by nucleophilic displacement on a-chloro- or a-hydroxyalkyl peroxides with hydrogen bromide produces a-bromoalkyl peroxides (78). 

Hydroxyalkyl Alkylene Dinitramines and Their Nitrate Esters. Nitrate esters such as N,N -bis-(2-nitroxyethyl) ethylenedinitramine. 

NO-C2 H4-N(N02 >C2H4-N(N02 >C2 H4 -ono2 (qv) were proposed as non-volatile plasticizers for NC in prepn of propellants. The method of prepn consists of the hydroxyalkylation of a nitramine (such as ethylenedinitramine) by means of an alkylene oxide (such as ethylene oxide), followed by nitration ... 

In contrast to isocyanates, isothiocyanates are relatively unreactive toward hydroxyl-containing compounds thus they are not even affected by aqueous media [31]. Their reaction with hydroxyalkyl thioureas has been reported [32]. With free 2-mercaptoethylamine, 1 mole of phenyl isothiocyanate gave the N-substituted product, l-(2-mercaptoethyl)-3-phenyl-2-thiourea, and 2 moles gave the N,S-disubstituted product. Isocyanates, regardless of the relative amounts, reacted with 2-mercaptoethylamine to give the N,S-disubsti-tuted products. Cleavage with silver nitrate affords the l-(2-mercaptoethyl)-3-alkylureas [33]. 

---