Shoolery's rule

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

where 0.23 ppm is the chemical shift of methane and the empirical adjustments 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

Shoolery's rule is a particular instance of a general class of rules of the form , with two substituents on methylene resulting in two parameters and .

References

External links Organic Spectroscopy: Principles and Applications, page 206