Re: "Chemists have a reputation for

Hey Don, PBS or one of the networks has documented Newton as being a
'closet alchemist', but who cares.
Newton's contributions to mankind are beyond measurement. Does anyone
really care?

Next, I suppose the documentaries will disclose that he was also
homosexual, but again, does anyone really care?

Newtons' accomplishments speak for themselves, and to mankind, that is
all that really matters. The simple facts are that no man living in
the 19th century mad any contribution that even came close to rivaling
those of Newton. You can take that to the bank! :-)

Harry C.







On May 17, 4:00 pm, "donald haarmann" <donald-
haarm...@xxxxxxxxxxxxxxxx> wrote:
being closet pyromaniacs, but the real crazies blow themselves up."

Nature 447, 141 (10 May 2007) | doi:10.1038/447141a; Published online 9
May 2007

Chemistry: Teetering on the edge
Emma Marris1

1. Emma Marris is a reporter for Nature based in Washington DC.

Abstract

Why do chemists make compounds that could blow up in their faces?
Emma Marris finds out...from a safe distance.
Explosives come in many varieties, from military munitions to rapidly
inflating airbags. But useful explosives share one thing: stability. A clear
advantage of trinitrotoluene, or TNT - whose punch is used as a yardstick for all
other explosives - is that it remains safe and solid until detonated. So why
would anyone want to make a highly unstable explosive? One that will release its
energy on the slightest provocation?
Because they are chemists, and they like explosions, is the popular
answer. Because they are chemists, and they like a technical challenge, is what
those doing the work say. How convincing is that?
Explosives release energy stored in chemical bonds in a runaway process
that often turns solids into gases, expands material massively and creates heat.
In big explosions, pressure waves radiate out from the origin, keeping the
reaction going throughout the material. When detonated, TNT decomposes
violently into a gas, some soot, and a boom. Many explosive compounds are less
stable than TNT - some are so temperamental or hard to make that they will
probably never be used in practice.
Consider this warning for tetraazidomethane, a particularly wild member of
the group of compounds known as polyazides, which have a general reputation
for removing student eyebrows. "Tetraazidomethane is extremely dangerous as a
pure substance. It can explode at any time - without a recognizable cause."
Klaus Banert at the Chemnitz University of Technology in Germany was
the first to synthesize this compound. He says that less than a drop of it
destroyed the glass trap and the Dewar flask of the cooling bath they used to
isolate it (K. Banert et al. Angew. Chem. Int. Edn 46, 1168-1171; 2007).
"Although we had expected explosive properties of tetraazidomethane, we were
deeply impressed by its destructive force," he says.
His team had to work behind a safety shield and wear gloves, face shields
and ear protectors. Banert says that when it was all over, he was relieved. The
lab had taken all reasonable safety precautions but he had still been worried
while the experiment was underway.
So why did they do it? Was it the adrenaline? The childhood lure of
explosions? Banert says that it was the pure challenge of the synthesis. "I
received my first chemistry set at the age of 11 and continued very intensively for
several years performing chemical experiments at home. I was also interested in
explosives at that time," he says. "But explosions were only of secondary
importance."
For tetraazidomethane, Banert says that it was an ambitious target to fill
this gap in the family of high-energy density materials. "The structure of
tetraazidomethane had already been calculated, and it was predicted that the
compound theoretically should be able to exist."
Derek Lowe, a medicinal chemist and author of the popular chemistry blog
'In the Pipeline' runs an occasional item on 'Things I Won't Work With'. Among
them are the polyazides. But he can see the appeal of making highly explosive
compounds. "These molecules do not want to exist. They are never going to form
naturally or spontaneously. These things are teetering right on the edge of not
being feasible, and you can be the first to make it."
To strengthen the case that it is the synthesis, not the destruction, that
excites such minds, consider the work of Philip Eaton at the University of
Chicago, Illinois. In the 1960s, Eaton made cubane - a cube with a carbon at
each corner. Then, at the suggestion of an army general, he went on to
synthesize a highly explosive compound called octanitrocubane (M.-X. Zhang, P.
E. Eaton & R. Gilardi. Angew. Chem. Int. Edn 39, 401-404; 2000).
Octanitrocubane has the same pattern, but with nitrogen dioxide bound to each
corner carbon atom. "The problem," says Eaton, "was how the devil to make it."
The tricky synthesis has, he explains, many, many steps. "In the course of the
whole thing we made less than a gram." Eaton can't estimate how much more
explosive it is than TNT, except to say "a lot".
The idea was that the density of the structure would pack a high explosive
power into a small volume - something that was important to the military when
bulky guidance-system computers were hogging too much space in missiles. But
octanitrocubane is just too hard to make for it to have any role in the military for
the foreseeable future. Eaton is just pleased he figured out how to synthesize it.
And he did it, he repeats, for the pure love of the challenge. "The explosiveness
has no allure for me at all. I was not the kind of kid who made explosives." The
proof? He never set off so much as a milligram of the stuff.
"There may be some folks who like that sort of thing, but they don't tend to
last very long," agrees Lowe. "Chemists have a reputation have a reputation for being closet
pyromaniacs, but the real crazies blow themselves up."

--
donald j haarmann
-------------------------------
Men offer love in hope of getting
sex; women offer sex in hope of
getting love; both are cheated.
Richard J Heedham


.

Relevant Pages

  • Re: "Chemists have a reputation for
    ... Emma Marris is a reporter for Nature based in Washington DC. ... Why do chemists make compounds that could blow up in their faces? ... But useful explosives share one thing: ... Because they are chemists, and they like explosions, is the popular ...
    (sci.chem)
  • "Chemists have a reputation for
    ... Why do chemists make compounds that could blow up in their faces? ... But useful explosives share one thing: ... Because they are chemists, and they like explosions, is the popular ... synthesize a highly explosive compound called octanitrocubane (M.-X. ...
    (sci.chem)
  • "Chemists have a reputation for
    ... Why do chemists make compounds that could blow up in their faces? ... But useful explosives share one thing: ... Because they are chemists, and they like explosions, is the popular ... synthesize a highly explosive compound called octanitrocubane (M.-X. ...
    (rec.pyrotechnics)
  • Re: "Chemists have a reputation for
    ... although many great scientists have died ... Why do chemists make compounds that could blow up in their faces? ... But useful explosives share one thing: ... Because they are chemists, and they like explosions, is the popular ...
    (rec.pyrotechnics)
  • Re: Liquid Explosives used aboard airliners
    ... | Do the chemists here concurr that the following is true? ... Both forms are explosives. ...
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