[taurean]

I am confused when to write app. and when to write approx. while doing the line listing in the H-NMR characterization data.

for example:  when to write app. q or approx. q

Thanks,

[taurean]

Could someone please answer? Thanks,

I am confused when to write app. and when to write approx. while doing the line listing in the H-NMR characterization data.

for example:  when to write app. q or approx. q

Thanks,

[discodermolide]

Well these days app. also has another meaning. So I would write approx. This removes any ambiguity.

[taurean]

Thanks.  My actual question was related coupling constants, how to determine if it is approx.

Could someone explain taking an example of quartet and approx. quartet/app.quartet or any other multiplicity?

Thanks,

Well these days app. also has another meaning. So I would write approx. This removes any ambiguity.

[discodermolide]

Well if your actual question was related to coupling constants why didn't you say that?
Your second question also makes no sense to me at all.
Perhaps you may like to provide an actual example of what you mean?

[fledarmus]

I'm not sure what you are asking either. Are you looking for the concept "appears as..."? I have seen this terminology used when a splitting pattern which should give two doublets overlaps to the point that the middle two peaks are on top of each other, and it is said to "appear as a triplet", or if there is enough asymmetry between the two peaks of a doublet that a doublet of doublets "appears as a quartet", but that terminology has almost disappeared in these days of high field NMR.