> I have some isochronous h-betas and if I assign them
> to the ambiguous hb* I notice that Analysis creates a
> brand new resonance and assigns that to one of the
> stereospecific betas (in this specific case hb2).
> Then all my resonances everywhere else are assigned to
> the other beta (hb3).
There is a bit of a tricky situation here. As Rasmus says non-methyl HB*
is really two resonances. So when you assigned a peak dimension as HB* a
new resonance was created and the two resonances were assigned to HB2 and
HB3.
In many ways I'd like to get rid of the dual HB* atom selection entirely,
but it remains as a convenience and nostalgia.
In your situation, when the HB* peak dim assignment was made, all other
peaks linked to the existing resonance would arbitrarily become HB2 or
HB3.
If you did not mean to sterospecifically resolve the betas then HB2/HB3
can be reassigned to HBa/HBb - this will still be annotated as HB* where
both are present on a peak dimension.
If the other peaks linked to the HB3 should also carry HB*, in the
Resonance Browser select [Show Shift List Peaks] for the relevant HB3
resonance, select the desired peaks, including the 'HB*' one and select
[Propagate assignments].
While it is possible to automatically propagate HB*, that is to say add an
appropriate HB2 resonance to other peak dimensions, there is no way to know
if this is always valid. It really is a user decision to say whether HB2
and HB3 are only visible as a single peak in a particular circumstance.
Different spectra under slightly different conditions or with different
resolving powers might see one or two shifts for the betas.
What I should perhaps add to Analysis are some more appropriate warnings
about what is going on when HB* is used.
T.
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