Also notable this article is by John Walker, co-founder of Autodesk, who passed last year.

I made this in high school, shortly after my AP Chemistry exam in 1992. I left it out to dry under the fume hood, and my teacher, not knowing what it was, moved it and BOOM! Fun times.

A fun thing to make. I made this in the high school chemistry room after school. Filter paper with some iodine crystals, pour some ammonia over and wait for it to dry (as I recall). I am not sure where I learned about it. Often my dad, who was a chemist then, would tell me little tricks like this. (He also turn me on to slathering a small amount of potassium permanganate with glycerin.)

Anyway, I was walking with it after I made it (when it was still damp and in the filter paper) and I accidentally dropped the filter paper in the school hallway. I picked up what I could (I suppose I should have gone back and mopped it up).

It was fun, the small explosions, like tap shoes clacking, when it was dry and walked upon. (Too bad it left brown stains on the linoleum.)

I was fortunate to have not had a large quantity dry. It can be pretty dangerous in large amounts I am told.

Oh wow! Growing up my chemical engineer uncle would come out on the Fourth of July and dump a bucket of stuff on the road in front of his house. A while later when it was dried he'd have us roller blade and skate board down the road to setup all the little explosions. It was a total blast. He refused to tell anyone what the compound was, but assured us it could be easily made. It has to be this stuff.

> There is no risk of terrorists using NI3 because anybody who made it in sufficient quantities to do serious damage would succeed only in blowing themselves up: those who do so are humorous, not terrible.

...not gonna say more, but, buried in the info and video there IS actually an idea for overcoming this nasty limitation (if you can mostly live up with "quasi-random detonation time", which could be acceptable for _some_ nefarious uses). Tbh I'd be more curious if any current gen LLM can figure it out.

Is there a good archive of this kinds of "not normally taught" chemistry things some where?

This does bring back fun memories! My favorite application was to make the game of ping pong a little more random. Small amounts scattered across the table would result in puffs of purple smoke and the ball changing direction.

I almost got banned from high school chemistry for making this (UK 1970's). Made it during break in middle of Chemistry lab while the teacher was out, and sadly was rather sloppy - got it over the floor, threw damp filter paper covered in it into the waste paper basket (which later self-detonated), etc.

The Anarchist Cookbook had a recipe for this IIRC, called ANTI (Ammonia Nitrate TriIodide). My chemistry teacher was not pleased at the pits left in the classroom countertops.

This was a favourite for me at school. Had a great chemistry teacher. Always had something that blew up available.

This was motivational until I did A level chemistry a few years later. He vetoed my attempts to make RDX out of hexamine tablets and normal nitric acid. He got suspicious when I was trying to dehydrate nitric acid with sulphuric acid.

Good job I gave up on chem or I’d probably be dead or in prison.

We used to steal Iodine crystals from the chem lab at High School, and set "traps" for the unwary. I have no idea how many clothes we ruined by putting NI3 on seats.

We also wired cans in || and wired up the boys' urinal so that they could "complete the circuit".

Ah, the Good Old Days before Workplace Health and Safety, or MDS.

> NI3 has no practical applications whatsoever

And yet almost every comment here is from someone who learnt or acheived something thanks to nitrogen triiodide.

I remember this from middle school science class, the purple cloud after was fun.

I made this for my high school chemistry project. We made it in the morning so it would be ready for our afternoon class.

It was drying in the chemistry back office and there must have been a draft. It exploded during a silent study hall.

Somehow they let us remake it for class that afternoon. We tried to put it on the floor as a joke, but our teacher was wearing sandals that day (no lab). She wasn't happy about it.

I originally got the idea (and prank idea) the previous year from a retiring chemistry teacher.

MIT has a long tradition of hacks, and among the first documented hacks in the 1870s for marching practice:

> in which students sprinkled iodide of nitrogen over the grounds of a military drill, causing explosions under classmates' boots.

https://www.slate.com/articles/life/culturebox/2012/02/mit_p...

Mr. Benzinger!

If you like crazy chemistry stories, be sure to read "Excuse Me Sir, Would You Like to Buy a Kilo of Isopropyl Bromide?".

One of the first stories in it involve the high school chemistry club breaking into the local college to get materials for some experiments. Along the way they find metallic sodium in kerosene and take some by shoving it in someone's back pocket. After some time passes it predictably catches fire. But don't worry: they have water handy!

My dad talks about making this stuff as a teen. It started with a chemistry kit that came with all sorts of dangerous things they would never in a million years sell targeting to a kid again. This peaked his interest in chemistry and he came across nitrogen triiodide while researching at a library with actual paper books lol. The ingredients were of no difficulty to obtain back then. They made this stuff and had fun setting some of it off. But he then told me that the next day he and his buddy thought let’s go set off some more. But he thought about it and they both said but what if the stuff on the edge of the jar has dried? Yes they made a fairly big sample. They were too nervous to open it so he told me he dug a hole and carefully moved it and hurried it. It sucks that people do bad things with chemicals as I would love to play around with things like this carefully in a safe setting without risk of other being hurt.

This reminds me of triacetone triperoxide (tatp).

https://www.theregister.com/Print/2006/08/17/flying_toilet_t...

It's a great shame John Walker is no longer with us, he was a bright fellow (even though I thought his company's products were too expensive). I loved his Hacker's Diet book, a true techie's approach to dieting. Certainly worth a read if one's interested in such things.

No doubt those of us who've gravitated to this link like watching things that go bang so make sure you read Walker's link at the bottom of the Nitrogen Triiodide page to his article on FOOF—aka Dioxygen Difluoride (O2F2). Also, make sure you read the link in that page to Derek Lowe's blog in Science's site Things I Won't Work With.

Every chemist should read Lowe's blogs, they're not only informative but often entertaining. I've copied the FOOF link here for convenience (this truly is chemistry at the bleeding edge):

https://www.science.org/content/blog-post/things-i-won-t-wor...

triiodide is such a beautiful word. Great one for a bar bet on whether there are English words with two consecutive I's!