Physics:Shoolery's rule

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Shoolery's rule, which is named after James Nelson Shoolery, is a good approximation of the chemical shift δ of methylene groups in proton nuclear magnetic resonance. We can calculate shift of the CH2 protons in a A–CH2–B structure using the formula

[math]\displaystyle{ \delta = 0.23\,\mathrm{ppm} + S_\mathrm{A} + S_\mathrm{B} }[/math]

where 0.23 ppm is the chemical shift of methane and the empirical adjustments S are based on the identities of the A and B groups:

Substituent S / ppm
–CH3 0.47
–COOR 1.55
–COR 1.70
–C6H5 1.83
–SR 1.64
–I 1.82
–Br 2.33
–OR 2.36
–Cl 2.53
–OH 2.56
–OCOR 3.13

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