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Why do these protons appear at 6.9 and 6.93 ppm, at lower ppm value? I assumed it was due to the anisotropic effect, specifically I thought the circulating (pi) electrons induced a magnetic field which causes them to experience a stronger net field, and those that were lower were not being affected by the induced magnetic field. This is instead apparently due to resonance. How come it is due to resonance? Is the circulation of electrons (ring current) not affecting them all or instead is resonance the primary reason why some protons come lower than others?

Anisole

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    $\begingroup$ Yep its due to resonance I don't know what else there is to explain! $\endgroup$ Sep 28, 2023 at 2:18
  • $\begingroup$ Review the guide How to ask and Asking FAQs to prevent clarification requests, objections, down-voting or closure. $\endgroup$
    – Poutnik
    Sep 28, 2023 at 8:14

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It’s due to resonance as the methoxy group is an ortho-para electron-donating group by resonance.

Hence the ortho and para positions are more electron rich, so their protons are more acidic and further downfield.

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  • $\begingroup$ This is the textbook explanation. Here is a paper beyond the textbook, also considering the sigma electrons. $\endgroup$
    – Karsten
    Sep 28, 2023 at 20:14

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