Hi @pjalaie. Thanks for your suggestion. I actually believe that the current text section is correct and the extra section is incorrect and should be modified.
0:19 The n plus one rule only applies
0:21 when the neighboring protons
0:23 are chemically equivalent to each other.
Actually I spoke too soon. The problem is both the text and extra section are too vague.
(Recommend referencing images in extra section while reading this)
There are two different “equivalences” to track in ¹H NMR splitting:
Neighbors vs. the observed proton
For coupling to occur, the neighbors must be nonequivalent to the observed proton. If a neighbor were equivalent to the observed proton, it would be part of the same signal and would not split it.
Neighbors among themselves.
For the N+1 rule to hold, the N neighbors must be equivalent to each other. If the neighbors are non-equivalent to each other (different J’s), the pattern is not N+1. It becomes a multiplet of multiplets (e.g., a doublet of doublets).
General conclusion:
The text says: “based on the number of neighboring equivalent protons.” In my opinion (and based on this suggestion) the word equivalent is ambiguous, readers can misread it as “equivalent to the observed proton.” If neighbors were equivalent to the observed proton, they would be part of the same signal and would not split it. N+1 applies when the N neighboring protons are equivalent to each other (mutually equivalent), nonequivalent to the observed proton, and share the same J to that proton. If the neighbors are non-equivalent to each other (different J’s), the pattern is a multiplet-of-multiplets, not simple N+1.
Suggestion
In NMR spectroscopy, the {{c1::N+1}} rule predicts the number of peaks of a signal based on {{c2::the number of neighboring protons that are equivalent to each other (and nonequivalent to the observed proton)}}
This new suggestion, tho, removes a testable fact that you are looking at neighbouring protons. The word neighbor being tested is more important than the equivalency imo
My b put the c2 in the wrong place. Intended to just mirror the original placement. Editing now. (Now fixed)
@anking-mcat-maintainers just calling attention to this one again. lmk what you guys think (no rush though just didnt want it to be lost)
Sort of as above:
the protons are equivalent to each other, are non-equivalent to the proton of interest.
That being said, the suggested phrasing I think almost ends up being extra long
If we want to take out time and space to elucidate the details here, the Extra field might be better-suited imo.
The card as-is isn’t perfect, for sure, though neither is it a card for which we’ve gotten a lot of evidence of confusion that I recall