Sciencemadness Discussion Board

Nitrogen Triiodide

MR AZIDE - 11-6-2012 at 11:05


I have easy access to 10% ammonia soln, and had synthesized a few Grams of nice iodine powder a few weeks ago, which is now happily sitting in the sample tube turning the polytheme lid black:P.

Question is, is the 10% ammonia soln, concentrated enough to make the NI3.......????

If so how long does the iodine need to be immersed in the solution, to react to NI3..........

Im just curious Ive never made any of this stuff before, If I make some NI3, it will just be a very small amount, as a chance to observe its instability.

Ral123 - 12-6-2012 at 10:10

It's not like we are all exploding iodine experts :D Everybody has done it, nobody has kept interest in it.

TheAMchemistry87 - 12-6-2012 at 18:27

it is if the ammonia is close to the iodine to check tap it hard with proper protection gloves,faceshield etc. if it blows up you made nitrogen triiodide

hodges - 15-6-2012 at 18:24

I remember some years back doing a test making nitrogen tri-iodide using both concentrated and household NH4OH. They definitely both worked; as I recall the product made with weak NH4OH was more sensitive.

I was once even able to get a "bang" from a kewlish experiment mixing tincture of iodine (do they even still make that?) and household ammonia. Didn't think it could actually be done that easily but it did work. As I recall, I used the whole bottle of tincture of iodine since there is so little actual iodine in it.

[Edited on 6/16/12 by hodges]

bahamuth - 15-6-2012 at 18:38

I have made several hundred of grams og nitrogen triiodide divided over several batches by grinding iodine crystals in a mortar covered by ammonia, dilute or concentrated doesn't matter much but a more stable product is achieved by the concentrated ammonia. The product may be washed with ethanol but not with acetone to remove water, water degrades the product, and stored wet with ethanol for quite some while before total degradation. In my experiments nitrogen triiodide reacts with ketones forming lachrymatory compounds.

A fun party trick is to drop ethanol wet nitrogen triiodide blobs somewhere and observe when they dry and someone distrubs them:P

JustMe - 15-6-2012 at 19:21

In the really old days they would make land mines for flies.

Wet paper with dilute sugar water, tear it up into small pieces and spread the nitrogen iodide onto the pieces, separate them and leave them to dry. Keep in mind that dry NI3 is very dangerous!!!!

So a fly would be attracted to a piece, land and be disintegrated. I heard it was great fun, although I never did it. My experience with NI3 consisted of encountering some the first day I attended college. Walking up the stairs to a dorm I noticed a black powder spread thinly on the steps and purple stains. Ah ha! Somebody had placed this as a joke. Some joke! Fortunately there wasn't a lot and it was spread thinly... Still there were small puffs and bangs as people walked across it. Ah, the 1970's - so innocent compared to today. LOL

mineralman - 16-6-2012 at 00:08

BET ME TO IT,,,, THE EXPLODING PURPLE PUFF OF NTI SMOKE FLY KILLER.
Best time with it..I came up with the idea of soaking cartridge paper in it, cut into squares and placed under the toilet seat feet, useing some corragated card to leave enough space for it to dry in place untill my woman got back from work and set the stuff off. he he he MM

plante1999 - 16-6-2012 at 02:45

Quote: Originally posted by mineralman  
BET ME TO IT,,,, THE EXPLODING PURPLE PUFF OF NTI SMOKE FLY KILLER.
Best time with it..I came up with the idea of soaking cartridge paper in it, cut into squares and placed under the toilet seat feet, useing some corragated card to leave enough space for it to dry in place untill my woman got back from work and set the stuff off. he he he MM
It's not funny, you can injure her with an energetic compound.

dann2 - 16-6-2012 at 02:49


Killing flies using this method was banned in 1983 (or there abouts).

mineralman - 16-6-2012 at 03:04

I didn't produce a powerfull TNI, iF ID WEIGHED, CALCULATED, ADJUSTED FOR OPTIMUM TEMPS AND MOST IMPORTANTLY "NOT POSITIONED THE CORROGATED CARDBOARD TO PREVENT SUCH THINGS HAPPENING, THEN i WOULD HAVE TO AGREE. (Oops) But I do have an understanding of explosives and controling energetic direction.
other factoring in info, like she sits foward with minimal weight when first she gets back from work, later on when she forgets shes not still in the factory and 500 strange women haven't used the loo seat previously, I wouldn't have even concidered it.
But thanx for pointing it out, I have a tendancy to forget there are others out there who don't fully understand that its one of the most dangerous and highly explosive compounds in the world, and as such its never made in large quantaties as a puff of wind can set it off. MM

mineralman - 16-6-2012 at 03:11

Quote: Originally posted by dann2  

Killing flies using this method was banned in 1983 (or there abouts).


WHO'S RESPONSABLE FOR THE POLICEING OF THAT LAW THEN?LOL

What prompted it to get that much attention? anyone try using it?

Swede - 16-6-2012 at 06:53

NI3 is an amusing lab curiosity when made in insanely small amounts. Tiny flecks go off with the noise of one of those throwing popper fireworks toys, and as described in this thread can be used for some fun tricks when some intelligence is applied... like never making more than a few milligrams at most.

I have heard of a thumbnail being lost when a coin was coated with too much NI3 and set in a public area.

One standard trick was to scoop minute amounts (wet, of course) into a flexible metal lab spatula. Give it a strong flick in a hallway, and the hallway is seeded with invisible amounts, well spread out. When done properly, anyone walking on it sounds exactly like a guy walking on rice krispies cereal or similar. Crunch, crackle... Their puzzlement is what makes it so funny, because the flecks are literally too small to see :D They check the bottoms of their shoes, and basically skedaddle out of there.

dann2 - 16-6-2012 at 08:19


According to Kurk Saxon the stuff makes great stuff for getting rid of rats. Spread it around and it terrifies them so much they leave the premises. (I have me doubts)
Dann2

AndersHoveland - 13-7-2012 at 11:07

About the structure of this compound, I think it can best be described as an adduct.
The NH3 is electron-donating to the iodine atoms in the other nitrogen atom, and so it is able to bond.
[+]H3N–NI3[-]

The iodine atoms, because there is an extra electron, are also able to cross-polymerize, much like how and iodide ion can combine with elemental iodine to form the triiodide ion, I3[-]. There is probably some complex resonance going on, and the negetive charge is distributed over several iodine atoms. Many of the bond orders are probably less than one.

[Edited on 13-7-2012 by AndersHoveland]

watson.fawkes - 15-7-2012 at 07:10

Quote: Originally posted by AndersHoveland  
About the structure of this compound, I think it can best be described as an adduct.
The NH3 is electron-donating to the iodine atoms in the other nitrogen atom, and so it is able to bond.
[+]H3N–NI3[-]
Provide a citation. I am sure that the actual crystal structure of NI3 is known. There's no need to fantasize one. Go find the relevant paper and report back here.

Morgan - 15-7-2012 at 08:35

I have read some literature that adds KI or ammonium iodide and was wondering if there is any real benefit.
One time I made some in high school with the approval of the vice principal and chemistry teacher and took most of it home. I guess that wouldn't fly in today's world. In English class I had very tiny amounts I played at my desk which made barely audible pops and crackles, the teacher heard something but continued on not quite sure if she had heard something or not.
After chemistry class the chemistry teacher and a few classmates played with it, you could actually feel your foot lift off a little when you stepped on it. There was a crowd that gathered outside the classroom curious about what was going on in the room.
That evening the chemistry teacher called my home and she cautioned me to be careful with it.

arsphenamine - 15-7-2012 at 12:12

As I model the NI3 monammine, it looks like the adduction is between the non-bonding NI3 pair and H-N HOMO, a hydrogen bond of sorts in which the N:H distance is ~2.8Å and constrained by Van der Waals effects from the iodine.

Like many ionic compounds (NaCl, P3N5), the adduct is an 'infinite' lattice in solid form.

froot - 16-7-2012 at 02:52

Many years ago I also played the fool with this stuff. Drilled a small hole in the end of a piece of chalk-board chalk and proceeded to load it with a small amount of wet NI3. The chalk would soak the moisture away and it would dry fairly quickly. Lets just say the result justified the punishment.
When a college I laid wet piles on the railing on the 5th floor overlooking an indoor atrium and went to class afterwhich I'd simply push the now dry piles over the edge with a piece of paper.

AJKOER - 17-7-2012 at 07:04

Two points. I recall reading that the power of an explosion versus the mass increases roughly by a cube law. So, if you increase the weight by a factor of 10, the power of the explosion may increase in the vicinity of a thousand fold (translation, serious injury and/or death becomes more likely).

I also recall reading somewhere on this forum of a high school chem student, who unknown to the teacher, made a more than a small quantity of NI3.NH3. It exploded in his face (luckily he was wearing eye protection). For days, he had to bear the embarrassment of walking around with a purple face.

Let's not all learn the hard way.


[Edited on 17-7-2012 by AJKOER]

Morgan - 17-7-2012 at 11:38

I read an account in a chemistry manual where some exploded in a flask that was still damp causing injury. I don't know how likely that is to happen but yes it's always a good idea not to make more than you want to explode in your face.