physics inclination - 29-6-2017 at 10:41
Hi, I was wondering if it would be possible in theory to make a molecule of acetylene aka ethyne C2H2, but with one or both of
the hydrogens replaced with nitro functional groups -NO2.
I wondered this because acetylene burns really hot normally, so maybe it could make a very powerful (and likely unfortunately unstable) energetic
compound if it were given nitro groups. It would also theoretically have a perfect oxygen balance, and actually produce only N2 and
CO2 on combustion; no water would be produced which would be interesting.
Alternatively, for a similar compound with a more oxygen-rich ratio, maybe take ethylene aka ethene C2H4 and add nitrate ester
groups -ONO2 to each end, one per carbon atom.
Again, I don't intend to try and make these, I wouldn't even know where to begin, I'm just curious if these are even theoretically possible to exist
(that is, without spontaneously igniting at standard temperature and pressure).
gdflp - 29-6-2017 at 11:35
As far as I know, no one has succeeded in preparing dinitroacetylene, though numerous attempts have been made. It does appear based on a quick lit
search that novel syntheses of nitroacetylene have been found, but I'll let those who are more experienced with EM give a more in-depth answer.
EGDN on the other hand has seen quite a lot of discussion on SciMad, see here.
Metacelsus - 29-6-2017 at 13:06
One could conceivably prepare the compound by reaction of a salt containing the acetylide dianion (such as Li2C2 or
CaC2) with a salt containing the nitronium cation (like nitronium tetrafluoroborate).
However, I would expect dinitroacetylene to be extremely, horrendously unstable. Even dichloroacetylene will readily and violently explode on contact
with air. (Incidentally, I once had some form as a side product of a certain reaction. It was quite the surprise.) I don't think one could isolate
dinitroacetylene, although it may be stable in cold, dilute solution.
[Edited on 6-29-2017 by Metacelsus]
PHILOU Zrealone - 30-6-2017 at 00:40
Did you use the forum search engine with as keyword "dinitroacetylen"?
Has already been discussed a lot...all that has to be known is written into previous treads.
O2NO-CH=CH-ONO2 doesn't exist yet...as can be theoricized nitrate esters of enols aren't very stable and readily form NO2(+)...For example phenol
nitrate turns immediately into nitrophenol.
******************
So more than probably
O2NO-CH=CH-ONO2 <--==> HO-C(NO2)=C(NO2)-OH (nitroenol)<--==> O2N-CHOH-CO-NO2
NO2 next to electronwithdrawing groups suffer from nitro-nitrite rearrangement and fast hydrolysis
O2N-CHOH-CO-NO2 ==> O=N-O-CHOH-CO-O-N=O =H2O=> HO-CHOH-CO2H + 2 HO-N=O
HO-CHOH-CO2H ==> O=CH-CO2H + H2O =oxydant like nitrous acid=> H2O + CO2
******************
Related compound has been synthetized by Klapote's team...(O2NO)2CH-CH(ONO2)2...glyoxal tetranitrate (or acetylen tetranitrate) itself brother of
methylene dinitrate (formaldehyde dinitrate)...those are potent explosive oxydiser of moderate stability.
[Edited on 30-6-2017 by PHILOU Zrealone]
physics inclination - 30-6-2017 at 18:56
Thanks for all the responses 
and I now realize that the second compound I described is just an inferior cousin compound to EGDN like you said, why didnt I see that before.
(edit at 22:00 June 30):
also sorry I did not search about these compounds before, as I did not know what the exact name would be (I did search google for a few names of what
I thought it would be and none turned up, not even results on pages here)
[Edited on 7-1-2017 by physics inclination]