Green Smash-Glow Crystals

Somewhat recently, I received the materials to try out NurdRage's "Smash Glow Crystals" experiment detailed here: http://www.instructables.com/id/Make-SMASH-GLOW-Crystals/
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For reference, the original procedure (summarized) to make orange smash-glow crystals is as follows:

100mL Dry Ethanol
2.93g Dibenzoylmethane
1.4g Europium(III) Nitrate
1.9mL Triethylamine

Combine all together in a flask and gently heat until everything dissolves. Let cool as slowly as possible to form crystals of the product, Europium Tetrakis (Dibenzoylmethide)Triethylammonium. Vacuum filter the crystals, rinse with a few portions of ethanol, and allow to dry. The crystals will be brightly fluorescent and triboluminescent, both of an orange color.
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I have successfully made a few crops of beautifully fluorescent and triboluminescent crystals following his process, and after doing this I had an idea: what if I substituted terbium nitrate for europium nitrate? Terbium has green fluorescence rather than europium's orange, so my goal was to produce green triboluminescent crystals in the end. Both elements are very similar chemically (as are most of the rare earths), and my thought was that I could substitute Tb(NO3)3 to get the different color effect.

I followed NurdRage's procedure again, except substituting 1.48g of Tb(NO3)3 for the 1.4g Eu(NO3)3 originally called for (to account for Tb's slightly greater atomic weight). My Tb(NO3)3 was home-made from nitric acid (also home-made) and terbium metal, the synthesis of which is detailed in my video seen here: http://www.youtube.com/watch?v=VGLPRTH8wok

Unfortunately, it looks like my idea did not work I was able to produce very nice crystals of what I expect are Terbium Tetrakis (Dibenzoylmethide)Triethylammonium, which have a green tint to them as opposed to the Europium variety's pale yellow. These crystals are somewhat larger and less "flaky" than the Eu-crystals. However, they do not fluoresce at all and show no triboluminescence when crushed. Does anyone have any ideas as to why my idea did not work? I was pretty optimistic that it would turn out, since the two rare earth salts are so similar chemically. The synthesis was very simple and ran just like the Eu-smash glow. The one difference I did note was that when adding my Tb-nitrate to the mixture, a white fog was produced that looked almost identical to the fog of NH4Cl seen when combining HCl and NH3 gases. Perhaps my terbium nitrate had some leftover nitric acid in it that fouled up the smash glow chemistry? Any thoughts are very welcome.

Quote: Originally posted by MrHomeScientist

The one difference I did note was that when adding my Tb-nitrate to the mixture, a white fog was produced that looked almost identical to the fog of NH4Cl seen when combining HCl and NH3 gases. Perhaps my terbium nitrate had some leftover nitric acid in it that fouled up the smash glow chemistry? Any thoughts are very welcome.

Right, some nitric acid should have felt in the Tb-nitrate. Next time store it in a vacuum exsiccator over KOH pellets for a few day.

The triboluminescense is a hard topic. A lot thing varies that will a crystal produce that effect or not. Uranyl-nitrate is also triboluminescent (gonna try it out soon), but it is not sure that neptiunium nitrate is also... So if it worked with Eu, it is not sure that Tb will also do it.

There is a simple and cheap way of making triboluminescent crytsals: not widely known but sugar (sucrose) is also triboluminescent, the only difference is that it emits light when it breaks in the UV region, so it is not visible to naked eye. BUT, if you dope the sugar crystals with rare earths or any UV active dye that the UV produced from the sucrose will cause the fluorescent dyes to glow, easy and cheap

Quote: Originally posted by kristofvagyok

Right, some nitric acid should have felt in the Tb-nitrate. Next time store it in a vacuum exsiccator over KOH pellets for a few day.

Terbium was a good idea.
It will work with other chemicals.

Use my method! Besides Terbium you will need potassium iodide and "phenazone" which can be found in some migraine pills:

http://www.versuchschemie.de/topic,16805,-gr%FCne+Tribolumin...



Video: http://www.dailymotion.com/video/xu3f3p_tribolumineszenz-ter...

Brighness of sugar is about 1 on a scale from 0-10.
The Eu-complex is 9, the green Tb-complex is 8. The Tb-complex was the brightest compound until the Eu-complex was developed in 1966.

Another almost equally bright compound is manganese-II-bromide triphenyphosphine oxide. This can be made with this description: http://www.chem-page.de/showexperimente/789-tribolumineszenz...



You will need MnBr2, Triophenylphosphine oxide and ethanol.
Much cheaper than Terbium.

[Edited on 23-10-2012 by Pok]

At the request of Brain&Force, here's a photo of my (presumed) terbium tetrakis(dibenzoylmethide)triethylammonium crystals. They appear slightly more green in person. This was taken under long-tube fluorescents, as it shows the green tint the best.

Quote: Originally posted by MrHomeScientist

Unfortunately, it looks like my idea did not work I was able to produce very nice crystals of what I expect are Terbium Tetrakis (Dibenzoylmethide)Triethylammonium, which have a green tint to them as opposed to the Europium variety's pale yellow. These crystals are somewhat larger and less "flaky" than the Eu-crystals. However, they do not fluoresce at all and show no triboluminescence when crushed. Does anyone have any ideas as to why my idea did not work? I was pretty optimistic that it would turn out, since the two rare earth salts are so similar chemically. The synthesis was very simple and ran just like the Eu-smash glow. The one difference I did note was that when adding my Tb-nitrate to the mixture, a white fog was produced that looked almost identical to the fog of NH4Cl seen when combining HCl and NH3 gases. Perhaps my terbium nitrate had some leftover nitric acid in it that fouled up the smash glow chemistry? Any thoughts are very welcome.