Re: Rotational energy barrier for CC triple bond

Not possible in acetylenic system since the two external bonds are sigma
bonds with very good rotation abilities!
CH3-C#C-CH3 will represent the problem like a car weel system...central
untwistable axis with two rolling rings.
Now you can play with a different molecule that would give you an
approximation of an intermediate barrier between C#C and C=C....
ketene familly is that intermediary.
H2C=C=CH2 <==> CH3-C#C-H

PhZ
[EMAIL PROTECTED] wrote:

> I am trying to get a "quick and dirty" value for the rotational energy
> barrier in a CC triple bond.  As a first guess, I would say about
> twice the value for a CC double bond.   Any data  that speak
> against this or for it?

> Thanks in advance.

> Roger




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Paul J. Franklin(moderator - sci.chem.organic.synthesis) 
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