Cyano substituted hydrazines

[hilbert2]

TL;DR

Cyanamide-type compunds from hydrazine, and their potential fuel application

Several articles describe n,n'-dicyanohydrazine being used as a reagent in chemical synthesis. Is there any reason why it would or wouldn't be possible to replace all the H atoms in hydrazine with -CN substituents? That n,n,n',n'-tetracyanohydrazine would look like a potential high energy fuel similar to dicyanoacetylene, which is the substance with highest known flame temperature.

 

[.Scott]

Hydrazine-1_1_2_2 tetracarbonitrile
wikidata
Google says: Based on chemical structure, this compound is likely to be a highly reactive, specialized chemical rather than a commodity chemical, and should be handled with extreme caution in a research environment.

I was unable to find an MSDS (or a vendor) for this chemical.

 

[hilbert2]

Thanks. Just had to find a correct IUPAC name for that chemical to find it, I guess. The PubChem page lists three chemical vendors, and it's said to be a solid with melting point between 70 and 80 degrees Celsius.

Even without any oxidizers mixed with it, that substance is likely to decompose explosively if heated enough, just like hydrazine and acetylene break down to H₂, N₂ and carbon when exposed to electric spark or heating. And small molecule hydrazines are often carcinogenic.

 

[Mayhem]

Please provide a reference to those articles.

 

[hilbert2]

Please provide a reference to those articles.

It's mentioned, for example, in this one: https://connectsci.au/ch/article-ab...nation-Polymer-formed?redirectedFrom=fulltext

In that paper, they describe trying to produce a tetrazole compound, which has a heterocyclic ring with only one carbon atom and four nitrogens, but then get an unexpected reaction product instead.

 

[Mayhem]

It's mentioned, for example, in this one: https://connectsci.au/ch/article-ab...nation-Polymer-formed?redirectedFrom=fulltext

In that paper, they describe trying to produce a tetrazole compound, which has a heterocyclic ring with only one carbon atom and four nitrogens, but then get an unexpected reaction product instead.

This is the only published article I could find, and googling 1,2-dicyanohydrazine (or N,N') only returns a few relevant links, one of which being this exact thread. Certainly an obscure reagent.

Anyway the hydrazine N-N is already reactive and a CN^{1-} group is electron withdrawing. Additional substituon would destabilize the bond furher through delocalization.

 

[hilbert2]

This is the only published article I could find, and googling 1,2-dicyanohydrazine (or N,N') only returns a few relevant links, one of which being this exact thread. Certainly an obscure reagent.

Anyway the hydrazine N-N is already reactive and a CN^{1-} group is electron withdrawing. Additional substituon would destabilize the bond furher through delocalization.

It's in this PubChem entry: https://pubchem.ncbi.nlm.nih.gov/compound/11170913

The patents linked there are written in Chinese or Korean so difficult to read, at least for me. The articles mentioning that compound really seem to just refer to the one I mentioned in the earlier post. But it should be an existing chemical as there seems to be a chemical vendor selling it and the web page mentions physical properties such as melting point and flash point.

If those hydrazine carbonitriles act as good chelating agents, one could probably produce a quite high-energy explosive by complexating something like the Cu²⁺ ion in Cu(ClO₄)₂ with that compound, but can't know how easily it would detonate by accident even from slight friction or heating. Here's an ammonia-complexated version of that: https://onlinelibrary.wiley.com/doi/abs/10.1002/prep.202000131

 

[Mayhem]

It's in this PubChem entry: https://pubchem.ncbi.nlm.nih.gov/compound/11170913

The patents linked there are written in Chinese or Korean so difficult to read, at least for me. The articles mentioning that compound really seem to just refer to the one I mentioned in the earlier post. But it should be an existing chemical as there seems to be a chemical vendor selling it and the web page mentions physical properties such as melting point and flash point.

If those hydrazine carbonitriles act as good chelating agents, one could probably produce a quite high-energy explosive by complexating something like the Cu²⁺ ion in Cu(ClO₄)₂ with that compound, but can't know how easily it would detonate by accident even from slight friction or heating. Here's an ammonia-complexated version of that: https://onlinelibrary.wiley.com/doi/abs/10.1002/prep.202000131

It is well known that a high nitrogen to carbon ratio in a molecule is a predictor of positive energetic properties. I can't find a common vendor that supplies the reagent in question, but I'm sure it's out there. Maybe on the Chinese chemical market.

Also, PubChem is a terrible resource as many entries are predicted computationally.

Not sure why you are interested in this. There's a billion ways to make unstable compounds. I find that exceptional stability is a much more interesting feature in non-trivial chemical compound

 

[hilbert2]

Not sure why you are interested in this. There's a billion ways to make unstable compounds. I find that exceptional stability is a much more interesting feature in non-trivial chemical compound

One type of compounds I find interesting are these cubane-like carbon allotropes, which could be used for storing energy to little volume or mass, much like the polynitrogens and metallic hydrogen which are planned as high energy density materials.

https://pubs.rsc.org/en/content/articlelanding/2018/cp/c7cp08380g
https://www.sciencedirect.com/science/article/abs/pii/S0009261498007623

 

[Mayhem]

Energy storage is one of my areas of interest and indeed, energy density is a key parameter for storage viability.

But reversibility, in the sense that you can 'recharge' your storage device is as important for general applications.

 

[hilbert2]

But reversibility, in the sense that you can 'recharge' your storage device is as important for general applications.

Nowadays there seem to exist capacitors of hundreds of Farads for sudden energy release, which is a bit surprising if one hasn't seen that before.

https://en.wikipedia.org/wiki/Supercapacitor

Sorry for having just a Wikipedia source, but it should be easy to find actual references.

 

[AlexB23]

TL;DR: Cyanamide-type compunds from hydrazine, and their potential fuel application

Several articles describe n,n'-dicyanohydrazine being used as a reagent in chemical synthesis. Is there any reason why it would or wouldn't be possible to replace all the H atoms in hydrazine with -CN substituents? That n,n,n',n'-tetracyanohydrazine would look like a potential high energy fuel similar to dicyanoacetylene, which is the substance with highest known flame temperature.

Apparently, this chemical is also in space. No idea why so many chemicals form up there, but it is interesting to know. I know that polycyclic aromatic hydrocarbons are in interstellar gas. Now the cyanamide?

https://www.aanda.org/articles/aa/abs/2018/04/aa32346-17/aa32346-17.html

 

[hilbert2]

Apparently, this chemical is also in space. No idea why so many chemicals form up there, but it is interesting to know. I know that polycyclic aromatic hydrocarbons are in interstellar gas. Now the cyanamide?

https://www.aanda.org/articles/aa/abs/2018/04/aa32346-17/aa32346-17.html

There's lots of ionizing radiation in space and that's why unusual chemical compounds can form there.

 

[AlexB23]

There's lots of ionizing radiation in space and that's why unusual chemical compounds can form there.

True. Atoms do weird stuff when radiation hits them. Have scientists used ionizing radiation in the lab to make the cyanamide, or is the process inefficient?

 

[hilbert2]

True. Atoms do weird stuff when radiation hits them. Have scientists used ionizing radiation in the lab to make the cyanamide, or is the process inefficient?

Here's an article about biomolecule formation triggered by high energy radiation

https://royalsocietypublishing.org/...med-complexity-abiogenesis-as-a-by-product-of

I suppose several experiments have been conducted to mimic the environment that existed on Earth before first actual living cells formed. There was no ozone layer at the time, because an oxygen atmosphere requires a thermodynamic disequilibrium maintained by pre-existing bio-organisms. So a lot more ionizing radiation reached Earth's surface than at present day.

 

[AlexB23]

Here's an article about biomolecule formation triggered by high energy radiation

https://royalsocietypublishing.org/...med-complexity-abiogenesis-as-a-by-product-of

I suppose several experiments have been conducted to mimic the environment that existed on Earth before first actual living cells formed. There was no ozone layer at the time, because an oxygen atmosphere requires a thermodynamic disequilibrium maintained by pre-existing bio-organisms. So a lot more ionizing radiation reached Earth's surface than at present day.

Basically zapping primordial soup to make organic substances? Reminds me of that 1950s experiment, the Miller-Urey experiment.

 

[Borek]

True. Atoms do weird stuff when radiation hits them. Have scientists used ionizing radiation in the lab to make the cyanamide, or is the process inefficient?

Thing is, space is quite an exotic place - very low pressure, very low temperature, molecules are so separated they very rarely have occasion to interact with each other. That promotes highly unusual reaction paths which are quite interesting, it is just that reactors with volume measured in cubic parsecs are impractical

 

[AlexB23]

Thing is, space is quite an exotic place - very low pressure, very low temperature, molecules are so separated they very rarely have occasion to interact with each other. That promotes highly unusual reaction paths which are quite interesting, it is just that reactors with volume measured in cubic parsecs are impractical

That makes my mind go boom. Fascinating stuff. Most people, especially myself when I was younger thought that space is mostly empty, and particles would not interact with each other. But after learning about nebula, space appears to be a place teeming with chemical reactions.

 

[Jeremy O]

How about azide substituted hydrazines? No carbon, loads of energy, clean, all nitrogen, probably very unstable.

 

[Mayhem]

How about azide substituted hydrazines? No carbon, loads of energy, clean, all nitrogen, probably very unstable.

You mean as in R₁-N-N-R₂ where the R's are some type of azide? Right, we're just straight up discussing potential energetics now. Probably best if this thread isn't allowed to live further.

 

[hilbert2]

Molcalc estimates that the enthalpy of formation of N,N'-dicyanohydrazine is about +527 kJ/mol, which means that it is a very high-energy fuel but possibly has to be stored at lower than room temperature to not convert to other compounds (including organic cyclic molecules with both nitrogen and carbon atoms). If both cyano groups are on same nitrogen atom (N,N-dicyanohydrazine), then the estimated value is +462 kJ/mol.

Dicyanoacetylene, which has the highest measured flame temperature for any fuel, has $\Delta H_f^0$ of about 500 kJ/mol.

 

[synch]

I think that it would polymerise and further react as soon as it condensed into liquid or solid, it may fleetingly exist as small concentrations in space at low temperatures