Sciencemadness Discussion Board

Remarkable Thermochromism in CuI(py)

ssdd - 9-5-2011 at 11:35

Recently I was synthesizing the fluorescent copper compound outlined on woelen's webpage, impressed by the neon yellow fluorescence I went on looking for some literature about the compound.

In the abstract of one paper I read the following:
Quote:

(Cu py)I shows yellow fluorescence at room temperature which reversibly changes to orange, then to red and finally to violet by cooling in liquid nitrogen („fluorescence thermochromism”). The last named compound is spontaneously decomposed by benzene to form highly dispersed copper iodide, which fluoresces red at room temperature, but not at all in liquid nitrogen.


So of course I had to try it! (I am one of the lucky few who has access to 180L of liquid N2 on a daily basis)

The results were visually stunning (one of the coolest things I've ever seen)...

Here's a GIF showing the compound as it warmed up to room temp above a liquid N2 bath: http://deepnorth.info/rand/net/0.gif

Some other still images:
http://deepnorth.info/rand/net/1.JPG
http://deepnorth.info/rand/net/2.JPG
http://deepnorth.info/rand/net/3.JPG

Here is also one last one showing the very weak red fluorescence produced when the compound is decomposed with benzene: http://deepnorth.info/rand/net/4.JPG

Hope you all enjoy!
-Tim, ssdd

[Edited on 9-5-2011 by ssdd]

blogfast25 - 9-5-2011 at 12:15

Nice. What's the py stand for?

ssdd - 9-5-2011 at 12:19

Ahhh, I probably should have mentioned that, its pyridine.

bahamuth - 9-5-2011 at 12:24

COOL!!

Have also made this CuI-Pyridine complex, the fluorescence is awesome with very high quantum yield.
But that it could be even awesome I had no idea.

Will try shortly the same as I have access to the facilities mentioned.