[chalconix]

Hello there! I read the forum topics for months now but never posted before!

I wanted to ask a question for H-NMR.

I have a spectrum including 2 AB aromatic protons that appear as distorted triplet. How can i write this down when i do the assignment? I thought to write it down as (dd,2H) but i don't know if this is the right way.

Thanks in advance...

 

[alphahydroxy]

I think your description is fine - it is what I would do I reckon.

[frenchy]

if you quote as a dd, or triplet, you're expected to quote the J value as well. It's worthwhile in this case to quote it as a multiplet.

[chalconix]

Thanks for your replies!

@frenchy
Generally (and also in cases like this at all of my compounds) i calculated the J where it was possible to calculate it. When there was no strange "mixing" of doublets etc... They are all novel compounds which i synthesized so i did what i could.. I also have in the molecule trans protons at a double bond, for which it was NOT possible in 100% of the spectra to calculate the J of BOTH of the alkene protons (generally calculated as J=15.6 Hz).

[frenchy]

if you download the free version of MestRe Nova, you should be able to just measure it instead of having to calculate it. that is if your spectra are electronic

[chalconix]

It is not accurate.. very small changes at where you point your mouse make 0.3-0.6 hz difference. On the contrary, the peak in ppm is always one number