Increment system for estimation of chemical shifts of benzene carbons
Formula:
| Substituent | ipso | ortho | meta | para |
| -H | 0 | 0 | 0 | 0 |
| -CH3 | 9.3 | 0.6 | 0 | -3.1 |
| -C2H5 | 15.7 | -0.6 | -0.1 | -2.8 |
| -CH(CH3)2 | 20.1 | -2.0 | 0 | -2.5 |
| -C(CH3)3 | 22.1 | -3.4 | -0.4 | -3.1 |
| -CH=CH2 | 7.6 | -1.8 | -1.8 | -3.5 |
| -CCH (alkyne) | -6.1 | 3.8 | 0.4 | -0.2 |
| -C6H5 | 13.0 | -1.1 | 0.5 | -1.0 |
| -CF3 | 2.6 | -2.6 | -0.3 | -3.2 |
| -CH2Cl | 9.1 | 0 | 0.2 | -0.2 |
| -CH2Br | 9.2 | 0.1 | 0.4 | -0.3 |
| -CH2OR | 13.0 | -1.5 | 0 | -1.0 |
| -CH2NR2 | 15.0 | -1.5 | -0.2 | -2.0 |
| -CHO | 7.5 | 0.7 | -0.5 | 5.4 |
| -COCH3 | 9.3 | 0.2 | 0.2 | 4.2 |
| -COOH | 2.4 | 1.6 | -0.1 | 4.8 |
| -COOR | 2.0 | 1.0 | 0 | 4.5 |
| -CONR2 | 5.5 | -0.5 | -1.0 | 5.0 |
| -COCl | 4.6 | 2.9 | 0.6 | 7.0 |
| -CN (nitrile) | -16.0 | 3.5 | 0.7 | 4.3 |
| -OH | 26.9 | -12.6 | 1.6 | -7.6 |
| -CH3 | 31.3 | -15.0 | 0.9 | -8.1 |
| -OC6H5 | 29.1 | -9.5 | 0.3 | -5.3 |
| OCOR | 23.0 | -6.0 | 1.0 | -2.0 |
| -NH2 | 19.2 | -12.4 | 1.3 | -9.5 |
| -NR2 | 21.0 | -16.0 | 0.7 | -12.0 |
| -NHCOCH3 | 11.1 | -9.9 | 0.2 | -5.6 |
| -N=N-C6H5 | 24.0 | -5.8 | 0.3 | 2.2 |
| -N=C=O | 5.7 | -3.6 | 1.2 | -2.8 |
| -NO2 | 19.6 | -5.3 | 0.8 | 6.0 |
| -SH | 2.2 | 0.7 | 0.4 | -3.1 |
| -SCH3 | 10.1 | -1.6 | 0.2 | -3.5 |
| -SC6H5 | 6.8 | 0.5 | 2.2 | -1.6 |
| -SO3H | 15.0 | -2.2 | 1.3 | 3.8 |
| -F | 35.1 | -14.3 | 0.9 | -4.4 |
| -Cl | 6.4 | 0.2 | 1.0 | -2.0 |
| -Br | -5.4 | 3.3 | 2.2 | -1.0 |
| -I | -32.3 | 9.9 | 2.6 | -0.4 |
| -??? |
Example: p-Cresol
