Friends,
I have been grappling with structure determination that hinges on the
difference between the effects of a nitro (NO2) and a nitroso (N=O)
substitution on aromatic ring 1H chemical shifts.
Does anyone know this off the top of their head?
More embarassing is that I couldn't find any listing of the nitroso in an
hour's search in the library. The new texts describe basic principles of
chemical shifts with sparse examples; the old texts provide short tables,
similar to Silverstein (which list nitro but not nitroso). I suspect that
programs which predict spectra from structures (e.g. ACD/HNMR) may have
replaced tables. But I am at variance with such a prediction and need a
few examples to either concede gracefully or support my case.
Would anyone be willing to share references to (1) their favorite tome or
database of chemical shift data of sample compounds; (2) a good exposition
for students on the subtleties in estimating shifts by inspection. I'll
repost an annotated bibliography if there are any gems.
-- Roger
Received on Tue Jun 27 2000 - 13:26:06 MST