Talk:Rhodium(III) chloride

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About putting some things in comments. I am going to revert them back after I can figure this article out more.

The dimerization of ethylene and the O2-Rh-py thing is interesting. And Rh(IV) too. The organic applications are huge obviously. Actually, I am not absolutely, absolutely sure that anhydrous RhCl3 is useless, but I have heard horror stories of students who order 100g of this stuff and it does nothing. The monographs are a little vague. Also on the exact speciation of RhCl3 in water.Smokefoot 16:22, 30 January 2006 (UTC)

All that I can find on the Cl(py)4RhOORh(py)4Cl] cation is Addison, A. W.; Gillard, R. D. and Vaughan, D. H., "Polarography of some rhodium(III) complexes", Journal of the Chemical Society, Dalton Transactions: Inorganic Chemistry (1972-1999), 1973, 1187-93. This came up in SciFinder. Smokefoot 17:40, 30 January 2006 (UTC)

The refs given in Greenwood & Earnshaw are nos. 17 & 18 on p1127, the discussion on superoxide complexes of Co(III), Rh(III). The specific ref for this complex is NSA Edwards, IJ Ellison, RD Gillard & B Mile, Polyhedron, 12, 371-4 (1993). They also mention JCS Chem Commun 851-3 (1992) as a general ref. Walkerma 03:46, 31 January 2006 (UTC)

"Rhodium is not an essential element, so it can be assumed to be unhealthy."

I am removing this statement, as it makes an incorrect conclusion. For example, strontium is non-essential, but its compounds are non-toxic. --Pyrochem 01:11, 10 February 2007 (UTC)

Is this correct?

Quote: "Inexperienced workers sometimes confuse the two rhodium chlorides, but their behavior is completely different". I question the reference to "two rhodium chlorides". The only difference is that one is hydrated and the other is not and I would expect the chemical properties to be identical. Compare anhydrous and hydrated Copper(II) sulfate. Biscuittin (talk) 13:17, 13 October 2009 (UTC)

Well copper is not rhodium is the snarky answer to your very legit question. Anhydrous RhCl3 and anhydrous CuSO4 are both nonmolecular (=polymers). The differing rates of their solubilizations reflects the differing strengths of the Rh-Cl vs the Cu-O bonds. Rh(III) is well known to form rugged, inert bonds. Cu(II) is equally well know to form labile bonds to ligands. Hydrated rhodium trichloride is something like RhCl3(H2O)3 (I forget), but the Rh centers is not knit together by Rh-Cl-Rh bonds but by weaker, more hydrolyzable hydrogen- and van der Waals bonds. At least that is my interpretation of the situation.--Smokefoot (talk) 17:26, 13 October 2009 (UTC)

I just looked it up (Hollemann, Wiberg - lehrbuch der Anorganischen Chemie, p. 1197, 91st - 100th edition): The Waterfree RhCl3 that is obtained by reaction of dry chlorine gas qith rhodium powder, doesnt even dissolve in water. Whilst the RhCl3 Hydrate is indeed soluble in water. It is obtaines by dissolving Rh2O3 in hydrochloric acid. they oth have different colours and chrystal structures.

There are many Chlorides that have completely different properties, depending on beeing the hydrates or not, like Ironchloride or aluminiumchloride. —Preceding unsigned comment added by 84.171.206.166 (talk) 12:07, 4 July 2010 (UTC)

Molecular compound

What is a "molecular compound"? Surely all compounds are molecular? Biscuittin (talk) 13:20, 13 October 2009 (UTC)

Great question, here is one perspective: Solid NaCl is a 3-d polymer containing no discernable NaCl subunits, so chemists call NaCl nonmolecular (or some semanticists would say that the entire crystal is one molecule). When NaCl dissolves, ions are the result, not molecules of NaCl. Things like chlorobenzene and RhCl(PPh₃)₃ are semi-isolated in the crystal - the solid is clearly consist of discrete, well separated molecules. Similarly, solutions of these things contain well defined molecules. We call such species molecular. Molecular vs nonmolecular is a handy way to classifying compounds: organic and organometallic chem is mainly molecular, salts and refractory solids are nonmolecular.--Smokefoot (talk) 17:26, 13 October 2009 (UTC)

Incompatibility of properties

In the first paragraph depending on the degree of hydration 'the material is either a dense brown solid or a soluble reddish salt' with the implication that the anhydrous substance is dark brown. In the next paragraph it is red-brown and insoluble. In the next the hydrated salt is red and soluble. However in the Properties box it is given as dark red, insoluble and deliquescent ! (Presumably a property of the trihydrate). Further on the solution is stated to be acidic ! (Likewise the trihydrate). All rather confusing. Arsenios99 (talk) 11:37, 26 July 2024 (UTC)

We editors are few and imperfect, and we editors rely on complaints and comments like this to improve. Thanks, --Smokefoot (talk) 15:44, 26 July 2024 (UTC)