This is one of the best chemistry videos, nay one of the best videos, full stop, I’ve ever seen.
The video accompanies a paper (abstract here, subscription needed for full paper) in Organic Letters about a photochromic molecule (one that can change between different forms when hit by light of some kind) that flips back and forth really quickly when UV light is shone on it.
The molecule changes from colourless to green, and that’s pretty much the best thing about it – so look at the video.
If you want to know more about the chemistry, which you might, then I can tell you that the molecules are hexaaryldiimidazole derivatives, and are a cyclic systems containing naphthalene units.
These kind of materials are used in spectacle lenses that change colour in bright lights. But really, just watch the video, that’s all you need to know.
[Hat tip: The Chem Blog]