A gorgeous photo of pressure sensitive nitrogen triiodide exploding at 1000 m/s is shown below.

by vastibadastoy from flickr photostream

From vastib

The photo was taken in the dark with the camera’s shutter open, and a flash triggered by a pressure sensitive detector.

Apparently this was submitted as part of a manuscript to the Journal of Chemical Education for an undergraduate lab demo measuring how fast the explosion propagates through the material. Unfortunately, it was rejected as too dangerous.

The decomposition reaction is…
$$! 8\text{NI}_3\text{NH}_3 \rightarrow 5\text{N}_2 + 6\text{NH}_4\text{I} + 9\text{I}_2 $$

Chemical details on nitrogen triiodide can be found from the MOTM page contribution by Simon Cotton: Nitrogen Triiodide

Note 1: Yes, that is Latex embedded into the blog post.
Note 2: Originally from the Chemistry Reddit: Nitrogen Triiodide Photo

Mitch