Sciencemadness Discussion Board

Stabilized Nitrogen trihalides?

Trifluoroacetic - 4-5-2011 at 15:26

Hi all!
I know that that all of the nitrogen tri-halides are shock sensitive but I was wondering if it is possible to stabilize them by complexing them and dissolving them in a solution so that they could be used for halogenating things. More precisely is it possible to complex nitrogen triiodide with something other then an NH3 molecule and then dissolve it in and organic solvent?


plante1999 - 4-5-2011 at 15:32

you should post this in general chemistry topic....

AndersHoveland - 4-5-2011 at 15:39

NF3 is not explosive...

and NBr3 is extremely difficult to prepare, simply reacting bromine with ammonia will not form any explosive, whereas chlorine forms NCl3 (if conditions are acidic), and iodine forms chains of NI3*NH3 (if conditions are basic). One cannot always generalize, the different halogens are not always interchangable in reactions.

Trifluoroacetic - 4-5-2011 at 15:58

I just found an interesting paper on the production of Nitrogen Triiodide Adducts. This is quite interesting. I wonder if these are useful for anything.

http://www.iupac.org/publications/pac/pdf/1977/pdf/4901x0067...

GreenD - 4-5-2011 at 16:58

I'm not sure about halogenating them but nitrogen triiodide is "safe" in solution of water.

Just don't let it dry out while you're at work...

Lets look at the chemistry...

You have ammonium hydroxide and you add iodine crystals. You create dissociation when in solution to NH3•NI3, creating a lattice, but not as ordered as the iodine crystals, thus lowering the energy.

When you let the solution dry out, a further dissociation of ammonia and water evaporate, leaving NI3 - increasing entropy significantly.

Finally, you have such a weak bond - Iodine is incredibly soft, while nitrogen is relatively hard, that the energy for activation of the dry, uncomplexed solid is small yet the energy released is enormous for you are breaking a solid and forming 2 gases (NH3 -> N2 + I2(g))

So to halogenate materials... The driving force for this reaction is the release of nitrogen and iodide as gas. The iodine will not form gas in a solution (atleast to my knowledge) so this half of the equation will be nullified - you intend to react it on a molecule.

So you are asking for NI3 + R-X -> N2 + R-I + ?

You may be on to something, HOWEVER. Testing this is surely asking for serious injury, for what if the reaction does become explosive in solution? You better be wearing a bomb suit, or at the very least hazmat material...

UKnowNotWatUDo - 4-5-2011 at 17:22

GreenD about half of what you just said makes little sense. Iodine is soft an nitrogen is hard? What? And the release of energy has nothing to do with reacting a solid to make gases. It has to do with bond energies being broken and formed. Gases tend to carry energy out of a system.

Trifluoroacetic - 4-5-2011 at 17:28

I don't have the equipment to try it. So I won't be. But I couldn't help but think that if NI3 could be stabilized and made to form an adduct with other nitrogen bases/ amines and diluted in a solvent it might make a strong iodinating agent.



Trifluoroacetic - 4-5-2011 at 17:31

no NF3 isn't explosive which is why it makes a great plasma etchant.