Are pyrroles any good for EM building blocks?

I've had this paper kicking around in my brain for about 5 years now. I never hear about pyrroles. Is that because they arent much use? Or because they are just unexplored. See image. sorbic acid and nitrite gives a methyl-pyrrole with two nitro groups already there. It just always struck me as odd. I wonder how useful that could be building something else off of it? Or if theres another acid that would respond even better to nitrite treatment.

Really, I ordered a big bucket of nitrite. So i'm on a theoretical nitrite bender.



[Edited on 19-11-2022 by Hey Buddy]

My first thought of potential when I saw the paper was thinking back to dpx-1 "non-traditional explosiphore" klapotke paper. Obviously a furoxan isn't a pyrrole, but I would never assume the Klapotke molecule would detonate @ 8245m/s 29GPa. I'm just curious if anyone knows anything about pyrroles before I start getting all mad-max lab in the old garage.



[Edited on 19-11-2022 by Hey Buddy]

Quote: Originally posted by Hey Buddy

I've had this paper kicking around in my brain for about 5 years now. I never hear about pyrroles. Is that because they arent much use? Or because they are just unexplored. See image. sorbic acid and nitrite gives a methyl-pyrrole with two nitro groups already there. It just always struck me as odd. I wonder how useful that could be building something else off of it? Or if theres another acid that would respond even better to nitrite treatment. Really, I ordered a big bucket of nitrite. So i'm on a theoretical nitrite bender. My first thought of potential when I saw the paper was thinking back to dpx-1 "non-traditional explosiphore" klapotke paper. Obviously a furoxan isn't a pyrrole, but I would never assume the Klapotke molecule would detonate @ 8245m/s 29GPa. I'm just curious if anyone knows anything about pyrroles before I start getting all mad-max lab in the old garage. [Edited on 19-11-2022 by Hey Buddy]

Those two examples of unusual- unconventional energetic materials are of course very interesting... but brings also into light the extreme complexity/versatility and possibilities of the HNO2 / NO(+) chemistry.

The heterocyclic chemistry is also quite wild and full of specific reactions depending onto the hetero atoms, their type, their electronegativity, their numbers and the insaturations into the cycle leading sometimes to aromaticity with help of heteroatoms non-binding doublets...

A simple comparison of pyrrole, furan and thiophene give you a hint of the effect of a single heteroatom change into a molecular structure...also the effect of increasing the number of heteroatoms of a single species like N by passing from a single N into pyrrole, to 2Ns, 3Ns or tetrazoles.

The cyclic penta-rings are of course of great interest into the EM world because of the compacity of the molecule...5 atomic cyclic ring members offers structurally some stability and compactness ... so density increase and less sensitivity/more stability.
Into the EM/HEM world... you often find pentaring energetic groups (like tertrazoles, furazans, furoxans, oxadiazoles, triazoles.

Heteroatoms often increase the density vs a conventionnal -CH= or -CH2-part because for an equivalent or near equivalent volume CH or CH2 weights 13-14g vs 14g for -N= or 16g for -O- or even 32g for -S-

The main problem is the very exotic/specific chemistry of such cyclic compounds and heteroatoms so variable from what we know and that change from position relatative to each other and position into the ring...

So you cannot easily put as much of what you want where you want to...also each group will change the properties of the ring and of the heteroatom but also the reactivity of each group already in place... it becomes a complex cards castle sensitive to wind and rain...

Thus OK two NO2 is better than one but 3,4 or 5 can seriously generate unstability or lead to inexistance...
See already hexanitrobenzene... that is difficult to get at that hexa-nitro level...it is powerful but unstable thermally and hydrolytically (turns into trinitrophloroglucidol - 1,3,5-trihydroxy-2,4,6-trinitrobenzene).

About your nitrite bending ("the last NO bender?"
I think that to buy and store a quantity of NaNO2 is a good idea... because general chemistry of NO(+), NO, HONO is really interesting and especially for some EnM... I will try to give hereafter... a tiny tour of those possibilities by working a bit onto your examples and other known EnM


[Edited on 22-1-2023 by PHILOU Zrealone]

Quote: Originally posted by Hey Buddy

Here in the USA I purchase NaNO2 from Duda Energy out of Alabama. I had a big order of NaNO2 from them at the time of this first post. They had a reallocation of nitrite and cancelled the order and removed nitrite from their catalogue. I talked to them on the phone, they expect to carry it again someday but dont know when. (I suspect it is all going to war). --Anyways, I realized after this loss of nitrite availability, without nitrite there are brakes put on your experimenting and testing -No azides, tetrazoles, DDNP. A challenge. I dont know of any clean high yielding reductions of NO3 to NO2 but I may try different reductions just to try and learn about the possibilities. If you can get NaNO2 take advantage of the availability. If Duda produces it again I will just buy the 50lb bag and pay freight next time for lifetime supply.