converting Fox-7 into much more powerful explosive

[Anders Hoveland]

The explosive/propellent "Fox-7" (1,1-diamino-2,2-dinitroethylene) could potentially be used as a precursor to a much more powerful explosive.

Oxidation with a hypochlorite solution would first form
3-amino-4-nitro furoxan, then further oxidation would lead to dinitroazofuroxan (DDF).

If this route is feasible, it could potentially be a very direct and convenient way to prepare DDF, since the commercial availability of Fox-7 is increasing as a specialty research propellent.

Dinitroazofuroxan (formula C4N8O8 ) is thermally unstable, has a detonation pressure of 460kbar, and a detonation velocity of 9.7 km/sec at 1.94 g/cm3. The compound was fairly sensitive, but not extremely so.

Wikipedia has an article for DDF, but refers to the compound by its alternate name, 4,4’-Dinitro-3,3’-diazenofuroxan.
the molecular structure of DDF is
NO2-(C2N2O2)-N=N-(C2N2O4)-NO2,
where (C2N2O4) represents a furoxan ring

It is known that the reaction of 2-nitroaniline with hypochlorite solution (at 0°C) produces benzofuroxan, so using Fox-7 in place of the 2-nitroaniline would probably still yield a furoxan compound.

[Anders Hoveland]

Having actually seen the the original reference, the 10,000 m/sec detonation velocity that wikipedia states for DDF is certainly not a precise measurement or calculation.

It is quite possible that the crystal density of the compound is actually 2.02 g/cm3, as wikipedia states. Sometimes, in these sorts of situations, there exist more than one measured density value for the same compound in the literature. Usually the larger value is correct, as often the substance being measured was not in its most compact form. One really cannot blame researchers for not wanting to work with a big sample size, then boil out all the solvent and squeeze it down to get rid of potential little air bubbles, when the substance could likely explode! Another problem is that some of these energetic compounds have thermal stability problems. Trying to melt it down or boil out all traces of solvent is likely to cause some minor decomposition, which will upset the results.

Assuming that DDF actually has a 9.7 km/sec at a density of 1.94 g/cm3, and assuming its actual crystal density is 2.02 g/cm3, a calculation can be made.

square root of (9.7^2 * 2.02/1.94 ) = 9.89797959

that is to say that the square of 9.7 times 2.02, divided by 1.94 is 97.97. then the square root of that is 9.89797959.
you might wonder why the 9.7 was squared, and then the square root was later taken. This is because energy is proportional to the square of velocity, the relationship is not linear. 9.7 * 2.02/1.94 would actually have given an even higher value of 10.1.

If the values quoted in the literature from both sources are correct, which is a big assumption, then DDF actually has a detonation velocity of about 9,898 meters per second, in its densest form. Remember, this value should not be taken as a precise calculation, but rather as an indicative estimate.

These sorts of calculations can be used to help fill in gaps in knowledge about obscure explosives, for which there is little available research. Please feel free to share your own comments or opinions about this calculation.

[kkk]

Could this powerfull explosive be used for nuclear weapon(plutonium primaries) detonation.Is it too sensitive to be used for such purpose.How expensive/hard is to be produced in large scale for testing?