killswitch
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Functionalization and polymerization of cubane
I've heard that functional groups can be added to cubane, but I haven't been able to find any publications on this that aren't behind a paywall. I'm
having trouble understanding why the molecule doesn't fly apart during the transition stage. How did they go about adding those groups?
On a more advanced note, what procedures would lead to the synthesis of dicubylacetylene?
And perhaps polycubylacetylene?
Top left: ethyne bridges connected to adjacent carbons. (para?)
Top right: ethyne bridges alternate between adjacent and nonadjacent (but not antipodal) carbons. (hemimeta?)
Bottom right: No ethyne bridges are adjacent or antipodal (meta?)
Bottom left: Continuous straight chain of cubylacetylene monomers (ortho?)
What kinds of properties would these compounds possess? Conductivity? Geometry? Structural strength? Electron delocalization?
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bfesser
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Quote: Originally posted by killswitch  | | I've heard that functional groups can be added to cubane, but I haven't been able to find any publications on this that aren't behind a paywall.
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I would assume that the functionalization is done before the final C–C bonds of the cube structure are formed. If you're finding the
publications you're interested in, but have no access, try posting in the <a href="viewthread.php?tid=19098">Wanted References and Needed
Translations (8)</a> thread.
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kristofvagyok
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Funny guys 
Cubane chemistry is simmilar to get gloves and try to find something useful under the garbage.
Why?
Because simply preparing cubane dicarboxylic acid is a 4-5 month work in a well equipped orgo lab.
I know a few people who is working with cubane and cuneane (the stuff what is prodced if the cubane is contated with silver), and this kind of
chemistry is horrible.
For the 1-2dicubyl-acetylene. It is not impossible to make it, I have saw somewhere this kind of cubanes, but the problem is, when you want to
polymerize it then it will also effect the cubane, because it doesn't likes any metals, really strong bases or lewis acids what are usually
requirements of polymerization.
For the other acetylene substitued cubanes, I would say that they preparation would be much harder, then making a "simple" polymer from it what is not
good for anything.... Make polyvinylferrocene, it is also not so easy to prepare and it conduct's electricity. And a lot data is available from it,
not like from the cubane polymers.
I have a blog where I post my pictures from my work: http://labphoto.tumblr.com/
-Pictures from chemistry, check it out(:
"You can’t become a chemist and expect to live forever." |
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Ragbips
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1,4-dimethyl-cubanedicaboxylate shoud be quite easy to make.
I've tried for myself but the Favorskii rearrangement to form the second cubic structures failed and gave a black polymeric sludge, probably because
of lacvk of kinetic control.
I used Tsanaktsidis' synthesis from cyclopentanone. All other reagents are easily obtainable, and the Dowex 50WX8 I used is available in many types of
mesh and otherwise replaceble with a catalytic amount of any other acid.
From the dimethyl carboxylate you can make a lot of cubane derivatives. I could send you the Australian journal of chemistry article if you want, it's
pretty hard to find.
Edit: Australian, not Austrian
[Edited on 30-9-2012 by Ragbips]
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Mildronate
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Everthing about cubane is not easy! There was a time when students group in my university synth cubane.
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chemrox
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Ragbips- Yes! please post the article in refs. As a pdf if possible? Thanks!
"When you let the dumbasses vote you end up with populism followed by autocracy and getting back is a bitch." Plato (sort of)
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Ragbips
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I am not permitted to view that references forum somehow, but here it is.
Took me weeks to find it, university's library only had Austrian journal from 1997 and the article is from 1998.
It is Tsanaktsidis' improved synthesis, much less steps, better yield and more commercially available chems.
From the 1,4-dimethyl-cubanedicarboxylate (where the article ends) cubane can be made through Barton decarboxylation.
I've attempted this, and probably brominated it wrong. I did it for 5 days instead of 2, and protection from light was by packing everything in foil.
When light does enter the setup through a hole however, it will be reflected much more. I believe radical (Wohl-Ziegler like) bromination has occured,
either leading to misplaced bromination (disallowing Favorskii rearrangement) or radical polymerisation on the olefin part before or after the
Diels-Alder. It resulted in a black colloidal sludge unable to filtrate because the stuff would block any type of filter. Bromination itself gave a
red, very dense oil instead of fine off-white crystals and I couldn't get it to crystallise.
Attachment: 0189_192.pdf (305kB)
This file has been downloaded 625 times
[Edited on 3-10-2012 by Ragbips]
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