igor barsukov wrote:
> Just a little remark on Me-protons. Even if they are treated as
> ambihuous, the NOE intensity somewhat depends on the orientation of the
> C-C axis due to the fast rotation of the Me-group. People used to take
> this into account by adding 0.3-0.5A to the upper limit. Is there a
I think the distance correction of 0.3A for methylgroups
was proposed for the treament _with_ a pseudo-atom.
because of the rotation of the methylgroup
a smaller correction than the proton-geometric center distance
(~0.7-0.8 A?) is necessary.
I think the 0.3A comes from this publication (haven't checked)
T.M.G. Koning, R. Boelens and R. Kaptein,
"Calculation of the Nuclear Overhauser Effect and the determination of
proton-proton distances in the presence of internal motions"
J. Magn. Reson., 90 (1990) 111-123.
I don't know what kind of distance difference the effect you describe
leads to, I suspect it will be more subtle (smaller). Would be
interested if you have a reference.
Eiso
> possibilty to do this in the analysis? Probably will not have any effect
> on the calculated structure.
>
> Igor
>
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