1. Curryworks on March 1, 2013 2:02 PM writes...

Cu(II):TPMA in methanol

2. stop on March 1, 2013 3:26 PM writes...

anhydrous Ni(acac)2 in toluene is a fully soluable forest green solution

3. anon on March 1, 2013 3:34 PM writes...

Sm(II)I2 in THF is as purple/deep blue as it gets.

4. David Borhani on March 1, 2013 4:41 PM writes...

My organic favorite: N,N-dimethyl-4-nitroso-aniline (in solution). Deep, deep green. Na naphthalenide is a close runner-up. I also recall that Koelsch's stable free radical is (very dark, almost black) green in solution...not so pretty, but the crystals have an amazing metallic luster (one of the few samples I've saved from my days in the lab).

Koelsch's story is truly amazing and worth reading about. From his 1957 JACS publication:

The experimental work in the present paper was done in the Converse Memorial Laboratory of Harvard University in 1931-1932. when the author was a National Research Council fellow. A paper describing the work was submitted to THIS JOURNAL June 9, 1932, but it was not accepted for publication. The referee held that the properties of the chief compound, a,g-bisdiphenylene-8-phenylallyl, could not be those of a radical....

5. ScientistSailor on March 1, 2013 5:26 PM writes...

Work with pyrroles, you'll get lots of great green colors, although not by choice...

6. Jose on March 1, 2013 6:28 PM writes...

Jones oxidation- "the least fine green in lab."

7. MiddleO'Nowhere on March 1, 2013 7:36 PM writes...

Spiropyrans are always good for pretty colors. I had several functionalized 6-nitro-spiropyrans that were dark green and one that was a shiny, metallic green. Unfortunately, I can't find any pictures.

8. Organometallica on March 1, 2013 7:45 PM writes...

Cobalt is good for both this week's and last week's colors; take CoI2(dppe)2 and let it stir in ethanol at 70˚C for three days. You'll disproportionate from the gorgeous blue Co(II) to the Kermit green Co(I) and (III) species (both of which happen to be diamagnetic as well).

Then hit it with water and excess zinc, and then metallic cobalt will come out, coat your stir bar, and make it into a little caterpillar, easily the most adorable mistake I ever made in lab!

9. Lab Devil on March 1, 2013 8:13 PM writes...

Is that NiCl2*6H2O? Sounds like someone is trying a 1,4 selective hydride reduction. I tried one a few months ago, it didn't work. I wish you luck with your reaction.

But you are right about that color. Most of us deal with compounds that are some shade of amber or brown. That St. Patty's day green really does stand out.

10. Chemerson on March 1, 2013 10:16 PM writes...

I think I might have used this in an electroless nickel plating procedure on glass in an old lab. Very pretty solutions indeed.

11. souls_at_zero on March 1, 2013 11:45 PM writes...

First thing that comes to mind is an old post from Curly Arrow:

http://curlyarrow.blogspot.co.nz/2010/06/green.html

12. Martin on March 2, 2013 12:29 AM writes...

I tried, I really tried to resist the Blackadder quote but failed...

[Percy is surrounded by chemical apparatus. On the table in front of him is a green blob]
Percy: My Lord! Success! After literally an hour's ceaseless searching, I have succeeded in creating gold! Pure gold! Behold!
Blackadder: Percy, it's green.
Percy: That's right, my Lord.
Blackadder: Yes Percy, I don't want to be pedantic or anything but the colour of gold is gold. That's why it's called "gold". What you have discovered, if it has a name, is some "green".
Percy: [Picking up the blob] Oh Edmund! Can it be true? That I hold here, in my mortal hand, a nugget of purest Green?
Blackadder: Indeed you do Percy except it's not really a nugget is it? It's more of a splat.
Percy: Well yes, a splat today, but tomorrow! Who knows, or dares to dream?

13. A Nonny Mouse on March 2, 2013 2:34 PM writes...

Octabromo-Cu-porphyrin if you really want green which you can't get rid of (starts off a beautiful red/purple before the bromination). Just opened a couple of bottles to check the stock position and I have now cleaned the fume hood several times. I must admit that it was very finely divided for formulation purposes, but even the slightest trace lasts to homeopathic levels (I did get some on a grey sweatshirt 8 years ago and it's still hanging in there)

14. Markus on March 2, 2013 3:56 PM writes...

Nickel chloride is quite ubiqitious in biochem labs, used to prep chelating columns for Ni-affinity chromatography. Apparently another name for the compound is hospital green, or so I was told by an old prof of mine.

I was once eluting protein from a Ni-column with EDTA and to my surprise the eluate was blue and not green as expected. It turned out later the protein had a FAD prosthetic group, which is vividly yellow! Mix green and yellow and you'll get...

15. Daen de Leon on March 2, 2013 7:02 PM writes...

@Martin: I'll raise you the YouTube clip.

http://www.youtube.com/watch?v=TkZFuKHXa7w

16. cynical1 on March 2, 2013 11:52 PM writes...

You didn't mention the cool purple color you see momentarily before it goes black in the nickel boride reduction.

As a side note, I read in a review that nickel boride isn't flammable and I'm sure that the stuff you buy isn't. But on one of my larger scale reductions, the stuff starting glowing orange while I was filtering it. I guess everything you read in the literature isn't true. Who knew?

17. btm on March 3, 2013 11:52 AM writes...

PrCl3 in MeOH

18. Jordan on March 3, 2013 1:17 PM writes...

@ 13. A Nonny Mouse on March 2, 2013 2:34 PM

The perchlorinated Cu phthalocyanine is also very green -- and is used widely as a pigment (CI Pigment Green 7).

19. Dr. Demented on March 3, 2013 3:20 PM writes...

@14: Mix green and yellow and you get chartreuse, not blue.

20. TPP on March 3, 2013 5:30 PM writes...

iirc, plain old tetraphenylporphyrin in dichloromethane solution is a lovely bichromic green/red... very pretty in the sunlight.

21. Colonel Boris on March 3, 2013 6:51 PM writes...

Ah, Ni(II) - my old S = 1 friend. In coordination chemistry, it's amazing how often Co(II) and Ni(II) give different structures from the same reaction, just because Ni(II) wants to be that little bit more octahedral.

22. Anonymous on March 3, 2013 9:14 PM writes...

@14, Markus

Ni2+ + EDTA = blue complex

Plus, you get green if you mix blue+yellow, not the other way around.

23. Chemist Turned Hedgie on March 4, 2013 2:59 AM writes...

Let's not forget Grubbs I (I'm showing my age...) as a rather lovely purple solid or solution, shortly before it turns a nice orange at the end of a ring closing metathesis. Happy times....

24. simpl on March 4, 2013 5:42 AM writes...

re "Green is one of the harder colors..."
As a nine-year-old, I remember helping my younger brother on a school projct to extract some natural dyes, mainly out of flowers. The best green we got was from red wallflowers, which set us thinking. I became a chemist, he a banker.

25. myma on March 4, 2013 2:58 PM writes...

Polyaniline (emeraldine form) is a very dark glossy forest green, but only as a thin film. As a powder it resembles copier toner, a fine dark powder that gets everywhere.

26. gary on March 4, 2013 10:56 PM writes...

I think Derek is a closet fan of Black Adder (one of the finest comedies in the history of television).

https://www.youtube.com/watch?v=TkZFuKHXa7w

27. Trent Wallis on March 6, 2013 11:33 PM writes...

Potassium trioxolatoferrate(III), either in aqueous solution or as wonderful plates. Photosensitive though!

28. CurlyArrow on March 7, 2013 6:52 AM writes...

http://curlyarrow.blogspot.dk/2010/06/green.html