Nitryl salts

Reaction of the nitryl halides with strong Lewis acids yields nitryl salts with the linear N02" cation (92) (d(N=0) 115.4pm) (see Figure 16). 

Bubbling BF3 into a N2O5-CCI4 mixture at — 15°C gave the new nitryl salt (N02)2[(BF3)20]. The formulation was proposed from an analysis of the vibrational spectrum of this species. ... 

The fact that the ion derived from nitric acid in sulfuric acid is positively charged has been demonstrated by electrolysis experiments in which it was found that the nitric acid migrates from the anode to the cathode. Finally, it is noteworthy that several ciystalline nitryl salts have been isolated and characterized, e.g., N02" N03 , N02 C104 and N02 HS207 . 

O2N—N3 was made under similar conditions from a nitryl salt and lithium azide, but was not isolated. In acetonitrile solution it decomposed above -10°C [63]. 

With sodium azide, salts of secondary nitroparaffins rearrange to N-substituted amides (29). With SO2, primary or secondary nitroparaffins give imidodisulfonic acid salts (30). Potassium nitroform reacts quantitatively with nitryl chloride in ether to form tetranitromethane (31). 

Protonic initiation is also the end result of a large number of other initiating systems. Strong acids are generated in situ by a variety of different chemistries (6). These include initiation by carbenium ions, eg, trityl or diazonium salts (151) by an electric current in the presence of a quartenary ammonium salt (152) by halonium, triaryl sulfonium, and triaryl selenonium salts with uv irradiation (153—155) by mercuric perchlorate, nitrosyl hexafluorophosphate, or nitryl hexafluorophosphate (156) and by interaction of free radicals with certain metal salts (157). Reports of "new" initiating systems are often the result of such secondary reactions. Other reports suggest standard polymerization processes with perhaps novel anions. These latter include (Tf)4Al (158) heteropoly acids, eg, tungstophosphate anion (159,160) transition-metal-based systems, eg, Pt (161) or rare earths (162) and numerous systems based on tri flic acid (158,163—166). Coordination polymerization of THF may be in a different class (167). 

As stated above under TNMe, in Ger during WWII, the prepn of TeNMe by this process was scaled up for use as an intermediate and as a substitute for nitric acid in the V-2 rocket (Ref 26). A pilot plant was built at Newark, NJ for prodn using this procedure. It was destroyed by an expln in 1953 and not rebuilt (Refs 33 44). Other prepns of lesser importance are by the action of Ag nitrite on iodotrinitro-methane (Ref 3) by the action of 90% nitric acid and 25% oleum on malononitrile, yield 45% (Ref 40) by the action of mixed acid on a number of aromatic nitrocompounds, of which nitrobenzene, dinitrobenzene, and nitronaphtha-lene gave the best yields (Ref 13a) and by the action of nitryl chloride on salts of TNMe. 

The medium impact-sensitivity of this solid propellant component is greatly increased by co-crystallisation of certain impurities, notably nitryl perchlorate, potassium periodate and potassium permanganate [1]. The presence of certain minimum amounts of mono-, di, tri- or tetra-methylammonium perchlorates in the salt leads to a single step decomposition, at around 290°C for the monoderivative [2],... 

Nitropropane Nitrosyl fluoride Nitrosyl perchlorate Nitrourea Nitrous acid Nitryl chloride Oxalic acid See under Nitromethane chlorosulfonic acid, oleum Haloalkenes, metals, nonmetals Acetones, amines, diethyl ether, metal salts, organic materials Mercury(II) and silver salts Phosphine, phosphorus trichloride, silver nitrate, semicarbazone Ammonia, sulfur trioxide, tin(IV) bromide and iodide Furfuryl alcohol, silver, mercury, sodium chlorate, sodium chlorite, sodium hypochlorite... 

Nitroacetylenes are generally unstable and very explosive and so they have been little studied. Schmitt and co-workers used the nitrodesilylation of trialkylsilylacetylenes with both nitronium salts and nitryl fluoride to obtain nitroacetylenes. Dinitrogen pentoxide has also been used for the nitrodesilylation of trialkylsilylacetylenes. Nitrodestannylation of allylsilanes has also been reported. " ... 

Eremenko and co-workers used nitryl fluoride for the deamination of amines at subambient temperatures in acetonitrile. The same reaction occurs with primary nitramines and their alkali metal salts bis-nitramines react to give the corresponding bis-nitrate esters. 

Alkyl lV,lV-dinitramines (154) have been prepared from the reaction of the tetraalkylam-monium salts (155) of primary nitramines with nitryl fluoride in acetonitrile at subambient temperature. The same reaction with the primary nitramine or its alkali metal salts yields the corresponding nitrate ester. Treatment of the ammonium, potassium, or lithium salts of primary nitramines (156) with a solution of nitronium tetrafluoroborate in acetonitrile at subambient temperature yield alkyl iV,iV-dinitramines. ° The same reactions in ether or ester solvents enables the free nitramine to be used. The nitrolysis of A-alkylnitramides (157) and N,N-diacylamines with nitronium tetrafluoroborate in acetonitrile, and the nitration of aliphatic isocyanates with nitronium tetrafluoroborate and nitric acid in acetonitrile, also yield alkyl A,A-dinitramines (154). 

While the hydrolysis of N205 is believed to represent its major loss process, there are other possibilities that have potentially interesting implications under certain conditions. For example, N2Os reacts with the components of sea salt particles such as NaCl, NaBr, and Nal to form nitryl chloride, nitryl bromide, and nitryl iodide, respectively (e.g., Finlayson-Pitts et al., 1989a, 1989b Behnke and Zetzsch, 1990 Zetzsch and Behnke, 1992 Junkermann and Ibusuki, 1992 George et al., 1994 Behnke et al., 1994, 1997 Leu et al., 1995 Fenter et al., 1996 Barnes et al., 1991 Schweitzer et al., 1998) ... 

The nitronium salts of pentafluoroselenate(IV) and pentafluorotellurate(IV) of composition N02XF5 have been prepared23 from the reaction of selenium or tellurium dioxide with nitryl fluoride. 

Alkaline salts of nitramines arc oxidized by nitryl chloride to products possessing nitrogen in the highest oxidation state, i.e. the nitrate group.255 The free nitramines afford the nitrates in very low yields. 

Analysis of the Raman spectra of a variety of hexafluorometallate salts derived from reaction of N02F with metal fluorides, nitrosyl, and nitryl hexafluorometallates, indicates that the [N02]+ cation in the solids formed is linear (60b). 

Treatment of an epoxide, namely methyl 2,3-anhydro-4,6-0-benzylidene-oi-D-allopyranoside (78, Scheme 21), with nitryl iodide using methanol as the solvent has been reported.123 Rather than the expected nitration, opening of the epoxide occurred to afford 30% of methyl 4,6-0-benzylidene-3-0-methyl-oi-D-glucopyranoside (79), 10% of methyl 4,6-0-benzylidene-2-0-methyl-a-D-altropyranoside (80), and a water-soluble material. The water-soluble material was later determined to be a mixture of the 2-0- (81) and 3-0-methyl (82) products, with the benzylidene acetal removed, a result consistent with a later study.124 Performing the reaction in the absence of the silver salt resulted solely in formation of the water-soluble product. The preponderance of the diequatorial product 81 is in violation of the Flirst-Plattner rule, which predicts more of the diaxial product. The authors explanation for the anti-Fiirst-Plattner addition is as follows. 

Nitric acid is an active compound and its salts, the nitrates, are found in all fertile soils. The alchemists obtained nitric acid by heating alum and copper sulfate with nitrate in a retort. Owing to its powerful corrosive action, they named it aqua fortis or strong water. 7 It is also known as azotic acid, hydrogen nitrate and nitryl hydroxide. 

Aluminum powder also forms sensitive explosive mixtures with oxidants such as liquid CI2 and other halogens, N2O4, tetranitromethane, bromates, iodates, NaC103, KCIO3, and other chlorates, NaN03, aqueous nitrates, KCIO4 and other perchlorate salts, nitryl fluoride, ammonium peroxodisulfate, sodium peroxide, zinc peroxide, and other peroxides, red phosphorus, and powdered pol)Ttetrafluoroethylene (PTFE). 

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