chornedsnorkack - 5-3-2024 at 11:17
Inspired by thread of "Aluminum soaps", which, admittedly, is in "Organic chemistry"...
Wikipedia:
https://en.wikipedia.org/wiki/Metallic_soap
claims that:
"Theoretically, soaps can be made of any metal, although not all enjoy practical uses.[1]" Nora, Angelo; Szczepanek, Alfred; Koenen, Gunther (2001).
"Metallic Soaps". Ullmann's Encyclopedia of Industrial Chemistry.
Is that so?
Reason why many metals do not form carbonates is that they are reluctant to form cations, and their cations are strongly acidic. So you cannot produce
aluminum carbonate - you get aluminum hydroxide and carbon dioxide - but you can produce aluminum soap.
Are there any metals which resist production of soap because they give free fatty acid and metal hydr/oxide?
Can you produce bismuth soap? Niobium soap?
bnull - 5-3-2024 at 13:08
Bismuth, yes. Niobium, I'm not sure; probably yes too. Transition metals soaps can be used as catalysts. Bismuth stearate or oleate in the synthesis
of alcohols from olefines, for example, but I guess that's become obsolete.
It seems that each soap has very few (possibly only one or two) applications. Lithium soaps usually go to motor grease (I have a pot half-full) and
nothing else. I never heard of uranium stearate, for example. What would be the use of it?
[Edited on 5-3-2024 by bnull]
Lionel Spanner - 5-3-2024 at 14:36
When I did work experience in the analytical lab of a firm that made car parts from sintered metal powders (2001), one of the analytical tests
required tungsten stearate. I forget what exactly the test was; it was probably company-specific, as there seems to be very little information online
about tungsten stearate in general, and the company itself went to the wall many years ago.
What I do remember it was very dense, as you'd expect from a tungsten compound.
clearly_not_atara - 5-3-2024 at 15:17
If it forms an acetate, it should probably form a stearate. The reactivity of the carboxylate doesn't change much. But sometimes the acetate is not
saline, e.g. lead (IV) acetate.
I imagine you could make oleates of most metals by rxn of the metal perchlorate with Dr. Bronner's Magic Soap (potassium oleate).
[Edited on 5-3-2024 by clearly_not_atara]
walruslover69 - 6-3-2024 at 10:08
Once upon a time, I was synthesizing some CdSe quantum dots at university. We would mix Cadmium oxide (CdO) with oleic acid and heat to 150C - 225C to
form cadmium oleate, octadecane was used as the solvent and it dissolved easily. The oleic acid would exist on the surface of the nanoparticles and
helped stabilize and solubilize the nanoparticles. To the best of my knowledge almost all metal oxides or hydroxides will react with carboxylic acids.
teodor - 6-3-2024 at 23:58
There is a nice book "The alkaline-earth and heavy metal soaps" by S.B. Elliott (ACS monograph series 1946). It covers many metal soaps. Bi and Hg are
present. Probably I can make scan of some chapters, but the book is old and modern sources can contain more extended information. But Ullmann's
Encyclopedia of Industrial Chemistry can not.
As for aluminium soaps there is 1955 article (it is interesting, attached).
Attachment: mehrotra1956.pdf (439kB)
This file has been downloaded 125 times
[Edited on 7-3-2024 by teodor]
Attachment: rai1963.pdf (515kB)
This file has been downloaded 118 times