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New strongest acid

Chemists at U.C. Riverside have apparently discovered a carborane (a complex molecule of boron, carbon, chlorine and hydrogen) that they are claiming is the world's strongest acid. Details are here. Perhaps this provides an additional tool for the chemistry path to molecular nanotechnology.

4 Responses to “New strongest acid”

  1. rpiquepa Says:

    It's also one of the world's kindest acids

    About this worldís strongest acid, you also should read this article from Nature. It's a million times stronger than concentrated sulfuric acid and about a billion times stronger than the acids found in your stomach. But surprisingly, it's also one of the least corrosive. So you might soon find one of these new carborane acids, or superacids, in vitamins bought at your local drugstore. Even if this is not appealing to you, these researchers have other projects. They want to have fun by building molecules that have never been made before. Read more on my blog for other details, references and pictures of this superacid.

  2. Dr_Barnowl Says:

    Re:It's also one of the world's kindest acids

    Ok, not strictly nanotech, but I found myself wondering if this would have any use in redox battery electrolytes – presently, the state of the art is vanadium dissolved in sulphuric acid, but if this donates protons more effectively, it might perform better. Alas, I really don't know that much about the electrochemistry.

  3. Chemisor Says:

    Misleading term "million times stronger"

    > It's a million times stronger than concentrated
    > sulfuric acid and about a billion times stronger
    > than the acids found in your stomach.

    Puhlease! This is so incredibly misleading. Acid strength is measured on a logarithmic scale (pKa) of the equilibrium ratio of dissociation (Ka). The acid is not "a million times stronger", it "more strongly prefers the dissociated state" of H30+ and the conjugate base. This does not necessarily imply higher reactivity, because that depends on what you are trying to do.

  4. m2brew Says:

    This is an accurate description. Here's why.

    Actually these acids are never handled in the presence of water, so H3O+ is not a species of interest. This material is well beyond the scope of the aqueous acids taught in high school and intro college chem.

    This discussion is limited to Bronsted acids, or those that have an acidic hydrogen, H+. These acids can be written as HB, which means that the acid is a molecule B-, with an attached hydrogen H+. In aqueous solutions, weak acids are those that separate (dissociate) partially into H+ and B-, while strong acids are those that dissociate completely. The H+ that is formed in either case is by no means naked, but rather it associates with molecules of water. A notable point here is that although H3O+ is taught to be the form of H+ in water, the hydrogen atom prefers to be solvated by more than just one water molecule, forming things like H5O2+, H9O4+ etc., and the use of H3O+ is actually an oversimplification,

    However, H3O+ (the same as H(H2O)+) is the strongest form H+ can take IN WATER, and the acids mentioned do indeed make H3O+ in water. To get stronger, you need to use a solvent that is less basic than water. For example, if benzene were used as the solvent (benzene is a very weak base, much weaker than water), then the strongest H+ form you could have would be H(benzene)+. The carborane acids being referred to easily form H(benzene)+, while sulfuric acid does not do this at all. Neither does fluorosulfuric acid, which is over 1000 times stronger than sulfuric acid. Carborane acids will donate H+ to molecules that are even weaker acceptors than benzene, ones that are a million times weaker than what sulfuric acid will donate H+ to.

    So "a million times stronger" means that these acids can donate H+ to acceptors that are a million times weaker than what sufuric acid can donate H+ to. Given that Bronsted acids are defined as "H+ donors," the description as a million times stronger is valid. This definition is based on reactivity, it doesn't merely imply it.

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