Talk:Prussian blue (color)

"(note: this is not in the public domain, even though it is on a .gov site)" ... wtf?

The statement is both true (it's a private industry document, as noted by the copyright statement at the bottom of the page) which is provided by the U.S. government, but was not written by the U.S. government, so it is copyrighted) and irrelevant. I've removed it. Chuck 19:30, 20 September 2005 (UTC)[reply]

I posted a correction to the structure of Prussian Blue and less than a day later someone else changed it back. Since there seems to be some confusion (and since whoever changed it back does appear to know a few things about chemistry), I’ll post this here first and give everyone a chance to respond before I re-edit the article.

Prussian Blue is a cubic structure of Fe(II), Fe(III), and cyanide. In a perfect crystal of PB each Fe atom is coordinated octahedraly to six cyanide ligands, with Fe(III) coordinated to the carbon end of cyanide and Fe(II) coordinated to the nitrogen end. This structure would result in a net charge imbalance of –1 per formula unit. There are two ways that PB can adapt its structure to cope with this charge imbalance. First, it can incorporate alkali cations into the interstitial spaces of the lattice. Such cations are generally available during PB formation, since nearly all synthesis procedures involve the use of alkali salts like K₃Fe(CN)₆ or KCN. Second, it can randomly leave out cyanide ligands to correct the charge imbalance – this occurs to a large extent if an exotic synthesis procedure that doesn’t involve alkali cations is used, but will still occur to a smaller extent even if alkali cations are availale. If the PB is made in an aqueous solution (or simply left sitting out in air for very long) water will work its way into to lattice and coordinate to the Fe atoms where the cyanide ligands would have been.

You often see people write the formula as something along the lines of Fe₇(CN)₁₈ in an attempt to make the charges balance, but that’s not correct – and if you think about it for a moment, it should be clear you can’t form PB’s classic simple cubic structure if you have seven Fe atoms to every six cyanide ligand. -April 4th, 2006

I was the reverter back the formula back to hydrated Fe₇(CN)₁₈, although I expanded the section to explain the case further. This formula is what inorganic chemists accept PB per Andreas Ludi, who solved the structure.

I also used to think that the formula was as you indicate, which would certainly make PB easier to explain to students. You are referring to an expanded ReO3 structure - all metals octahedral with CN "rods" connecting them. Some PB relatives like that may exist, but PB is not one of them, at least according to inorganic dogma. PB is more complicated than the ReO3 motif - it is metal deficient. Take a look at the Ludi's paper or Dunbar's review. I realize that I possibly are being too dogmatic. Hence my comment that PB might be whatever blue stuff crashes out when you mix Fe(III) and ferrocyanide. Also, I agree with the implication of your comments - hydrated Fe₇(CN)₁₈ would have no ion-exchanging possibilities (unless one deprotonates Fe(III)-OH2 units, replacing H+ with Tl+ or Cs+). I admit to not fully understanding this bit, and I assume that the "medical grade" PB, used to sequester Tl+ tends toward the formula that you indicate, with K+ in the framework.

Thank you for taking the time to explore this issue on the Talk page, yours--Smokefoot 15:59, 6 April 2006 (UTC)[reply]

Question: There's a part in the article that reads, as of now, "14< x <16" as if this were some range of x values. Since x in this context would have to be an integer, if this is correct it should forgo using x at all and just put 15. If it should include 14 and 16 as possible values, it should either be "13 < x < 17" or "14 ≤ x ≤ 16" to be correct (if those aren't showing up properly for anyone, they should be less than or equal signs). As a math person, I had to point this out, I hope somebody takes the time to fix it, I would but I don't know which is correct. 149.43.x.x 01:47, 17 April 2006 (UTC)[reply]

Thanks, I didnt know how to write "≤."--Smokefoot 01:51, 17 April 2006 (UTC)[reply]

No problem, glad to be of help.149.43.x.x 06:19, 17 April 2006 (UTC)[reply]

If prussian blue is in fact used as a tool or gauge in metalworking, could someone add something about how it's used in that way in the article? Someone following the link from Measuring tools and gauges will be frustrated if there's nothing in the article about it. Chuck 19:36, 20 September 2005 (UTC)[reply]

I've heard that the term Prussian Blue was used to refer to the residue of Zyklon-B left in Nazi gas chambers. Can anyone confirm this information? Is it worth adding to the article? Pburka 18:45, 1 October 2005 (UTC)[reply]

In an earlier version of this page there was a paragraph about it:

Because of the above mentioned there is a controversy among pseudo-scientists trying to disprove the holocaust. It is a common argument that because the levels of cyanide (Prussian blue) are higher on the walls of the delousing chambers than the homicide chambers, the homicide chambers were not used to any extent. Anyone that understands the properties of iron bonded cyanide and cyanide gas can easily refute this.

But this was removed to maintain Wikipedia's NPOV. I feel as if it should be put back in the article, the NPOV violations arn't that bad, and easily editied.

Also removed (without explanation) were the references to the two bands which use the name Prussian Blue

In regards to the bands called Prussian Blue: The NPOV violations were getting terrible. The discussion board about the neo-nazi band Prussian blue turned into a "Jews are evil and control everything, all non-white races are crap" fun fest. It contained blatant, overwheming amounts of racism and anti-semitism. I think it was just too much to monitor.

Off topic material needs to go to a different page, reference by a dablink (See Wikipedia:disambiguation). I was going to do it myself, but the material (below) is too poorly written at this stage to use for a stub. -St|eve 21:52, 21 October 2005 (UTC)[reply]

Prussian Blue is the name of a singing duo from the United States. It is comprised of twin girls, 13 years old, named Lynx and Lamb. Their entire act is based upon their hatred of black people and Jews and their love of the Aryan race. Even at 13 years old they are very concerned about maintaining the purity of their race. This could possibly point to a promiscuous future in order to propogate their species more fully on the earth. They also enjoy dancing around a swastika symbol taped to their kitchen floor, and wearing Adolf Hitler smiley face shirts.

Their fame rose after the duo was featured on a segment of ABC's Primetime on October 20, 2005.

They derive their name from the color Prussian Blue, and from the fact that they claim to be German and have blue eyes.

I assume the chemical was invented in Berlin, hence its name. Is this correct? Bastie 03:48, 13 November 2005 (UTC)[reply]

It has been invented in Berlin by Diesbach, thus the name "Berliner Blau". The name "Preußisch Blau" comes from the fact that it was the color of prussion uniforms before they siwthced to camouflage "Feldgrau".

Can I add ferriferrocyanide as another name? It's listed on paint, but I don't know if it's chemically identical. Njál 15:48, 23 December 2005 (UTC)[reply]

What would happen if I mixed prussian blue paint with vinegar and then inhaled the vapour?

No clue, don't try it (sabrinaneo).

Isn't this some kind of antidote for something?

Nope. (sabrinaneo).

Yes, as mentioned in the article it can be used to treat some kinds of metal poisoning.