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POLYNITROETHYLENE

(CH 2 =CHNO 2 )n

Nitroethylene monomer, CH 2 =CHNO 2 , is a yellowish-green, strongly la-
chrymatory liquid, boiling at 35°C (at 70 mm Hg). It may be prepared by acting

with bases on 1-nitro-2-chloroethane or by the action of potassium hydrogensul-

phate on 2-nitroethyl alcohol (Wieland and Sakellarios [83]). Very satisfactory

results may be obtained with phthalic anhydride as dehydrating agent (Buckley

and Scaife [84]; Boileau and Runavot [85]; Sokolov, Perekalin et al. [98]).

It can also be obtained by acting with urea on 1,2-dinitroethane:

(29)

Nitrous acid then reacts with an excess of urea in the usual way.

Nitroethylene readily polymerizes to yield a white powder, insoluble in water

and in most organic solvents. It may be obtained by direct action of bases on nitro-

ethyl nitrate or -acetate or on dinitroethane.

Polynitroethylene burns without melting. It is a very weak explosive, which

gives a lead block test amounting to about 30% of that given by TNT. It has not

found any practical uses because of its low thermal stability.

A number of other nitro-olefins can be prepared in a similar way as nitroethylene

[86].

SYM-TETRANITROETHANE

This compound is known in the form of the potassium salt C(NO 2 ) 2 KC(NO 2 ) 2 K.

Its preparation and use in the production of hexanitroethane is discussed below.

HEXANITROETHANE

m. p. 142°C

The product is known as a colourless crystalline, rather non-volatile substance,

having explosive properties, It was first obtained by Will [87] when acting with nitric

acid on potassium salt of tetranitroethane:

C 2 (NO 2 ) 4 K 2 + 4HNO 3 -> C 2 (NO 2 ) 6 + 2KNO 3 + 2H 2 O (30)

For the preparation of the latter, Will applied Scholl’s method [88], consisting

in reacting potassium cyanide and nitrite with bromopicrin, according to the reac-

tions :