NMR of Aromatic Compounds

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NMR of Aromatic Compounds

• Lab

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Electrons Shield
General information
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Electron Withdrawing groups deshield by removing
electron density
General information
I suck
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Electron density can be added or removed through
the p or s systems
General information
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Ring currents usually deshield
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Toluene
An alkyl group does not shift the signal very
much. It is neither electron donating nor
electron withdrawing.
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Effects through the p system can be explained
through resonance structures
Electron withdrawing group
A lack of electrons will de-shield.
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Effects through the p system can be explained
through resonance structures
Electron donating group
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Di-substituted Aromatics
Para substitution gives a distinct splitting
pattern.
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skewed doublets
OCH3
Chemical shift (?, ppm)