Air & Water Reactions
Highly flammable. Slightly soluble in water.
Nitromethane may explode if heated or strongly shocked, especially if mixed with acids, bases [Handling Chemicals Safely 1980. p.687], acetone, aluminum powder, ammonium salts in the presence of organic solvents, haloforms (chloroform, bromoform), or hydrazine in methanol. Ignites on contact with alkyl aluminum or alkyl zinc halides. Reacts violently with strong bases (potassium hydroxide, calcium hydroxide), amines (1,2-diaminoethane, hydrazine), bromine, carbon disulfide, hydrocarbons, formaldehyde, metal oxides, lithium aluminum hydride, sodium hydride, strong oxidizing agents (lithium perchlorate, nitric acid, calcium hypochlorite). Reacts with aqueous silver nitrate to form explosive silver fulminate [Bretherick, 5th ed., 1995, p. 183]. Mixtures of Nitromethane and aluminum chloride may explode when organic matter is present [Chem. Eng. News 26:2257. 1948]. Nitromethane, either alone or in a mixture with methanol and castor oil, has a delayed but violent reaction with powdered calcium hypochlorite [Haz. Home Chem 1963]. Nitromethane reacts violently with hexamethylbenzene [Lewis 2544]. Nitromethane is strongly sensitized by hydrazine [Forshey, D. RR. et al, Explosivestoffe, 1969, 17(6), 125-129].
Behavior in Fire: Containers may explode
A colorless oily liquid. Flash point 95°F. May violently decompose if intensely heated when contaminated. Denser than water and slightly soluble in water. Hence sinks in water. Vapors are heavier than air. Moderately toxic. Produces toxic oxides of nitrogen during combustion.
Liquid may dry out skin and cause irritation.
Nitromethane is generally manufactured by gas-phase nitration of methane. The usual impurities include aldehydes, nitroethane, water and small amounts of alcohols. Most of these can be removed by drying with CaCl2 or by distillation to remove the water/nitromethane azeotrope, followed by drying with CaSO4. Phosphorus pentoxide is not suitable as a drying agent. [Wright et al. J Chem Soc 199 1936.] The purified material should be stored by dark bottles, away from strong light, in a cool place. Purifications using extraction are commonly used. For example, Van Looy and Hammett [J Am Chem Soc 81 3872 1959] mixed about 150mL of conc H2SO4 with 1L of nitromethane and allowed it to stand for 1 or 2days. The solvent was washed with water, aqueous Na2CO3, and again with water, then dried for several days with MgSO4, filtered again with CaSO4. It was fractionally distilled before use. Smith, Fainberg and Winstein [J Am Chem Soc 83 618 1961] washed it successively with aqueous NaHCO3, aqueous NaHSO3, water, 5% H2SO4, water and dilute NaHCO3. The solvent was dried with CaSO4, then percolated through a column of Linde type 4A molecular sieves, followed by distillation from some of this material (in powdered form). Buffagni and Dunn [J Chem Soc 5105 1961] refluxed it for 24hours with activated charcoal while bubbling a stream of nitrogen through the liquid. The suspension was filtered, dried (Na2SO4) and distilled, then passed through an alumina column and redistilled. It has also been refluxed over CaH2, distilled and kept under argon over 4A molecular sieves. It has been purified by zone melting at low temperature, or by distillation under vacuum at 0o, subjecting the middle fraction to several freeze-pump-thaw cycles. An impure sample containing higher nitroalkanes and traces of cyanoalkanes was purified (on the basis of its NMR spectrum) by crystallisation from diethyl ether at -60o (cooling in Dry-ice)[Parrett & Sun J Chem Educ 54 448 1977]. Fractional crystallisation is more effective than fractional distillation from Drierite in purifying nitromethane for conductivity measurements. [Coetzee & Cunningham J Am Chem Soc 87 2529 1965.] Specific conductivities around 5 x 10-9 ohm-1cm-1 were obtained. [Beilstein 1 IV 100.]
Rocket fuel; solvent for zein. Used in the coating industry.