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Carborane
Name: Vivian
Status: student
Grade: 9-12
Location: TX
Country: N/A
Date: January 2007
Question:
How was carborane - (H(CHB11Cl11) - created? What
reactants were there, and under what circumstances was the acid
made? Can a person make them without the use of any fancy lab materials?
Replies:
Vivian-
It would help me if you told me where you heard about this.
That way I can look it up, in case I have never heard of it before.
Which I have not. Fortunately, I found it at Wikipedia,
where you probably saw it too.
Your formula H(CHB11Cl11) refers to the "carborane superacid"
in the Wikipedia article "Carborane".
There are many carboranes. It is a family of molecules,
all built on the "carborane" base unit,
a ball of 12 Boron atoms with substitution of a carbon atom or two,
which adjusts its favorite charge state
and perhaps gives it a couple of specific handles.
Sorry, I suspect the methods to make it are not quite for amateurs.
Wikipedia footnotes refer to this article by Christopher Reed:
http://www.reedgrouplab.ucr.edu/publications/Chem%20Comm%202005%201669.pdf
which describes the process somewhat.
Since you are asking this question, you might actually like reading it.
I imagine they get some plain mono-carborane first,
then attach a lot of Chlorine atoms. I wonder if controlled addition of
Cl2 gas to the mono-carborane would work right
The article sounds like it does,
so some college-level amateurs might manage that.
Just like the benzene ring, a substitution on one corner
causes certain other corners to be favored next,
so substitution on several corners proceeds in nice neat steps.
Finally they carefully foist an H+ onto it.
That sounds like it involves some very unusual chemicals.
I do not think making the carborane units themselves
is an accessible thing for us.
It tends to start with borane gas (B2H6),
which most people cannot even buy
because it is pyrophoric and toxic.
Then there may be a series of self-condensations into larger boranes,
with distillation processes at each stage, in oxygen-free sealed tubes.
Reed says there's a newer way, but I haven't read about that yet.
Dicarba-dodeca-borane can be bought this year (2006), for only $50/gm....
Maybe next year the super-acid...
Jim Swenson
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