Increment system for estimation of chemical shifts of benzene protons
Formula:
| Substituent | Iortho | Imeta | Ipara | group |
| -H | 0 | 0 | 0 | |
| --CH3 | -0.18 | -0.10 | -0.20 | methyl |
| -CH2CH3 | -0.15 | -0.06 | -0.18 | ethyl |
| -CH(CH3)2 | -0.13 | -0.08 | -0.18 | isopropyl |
| -C(CH3)3 | 0.02 | -0.09 | -0.22 | tert-butyl |
| -CH2Cl | 0.00 | 0.01 | 0.00 | |
| -CH2OH | -0.07 | -0.07 | -0.07 | |
| -CH2NH2 | 0.01 | 0.01 | 0.01 | |
| -CH=CH2 | 0.06 | -0.03 | -0.10 | vinyl |
| -CCH | 0.15 | -0.02 | -0.01 | alkyne |
| -C6H5 | 0.30 | 0.12 | 0.12 | phenyl |
| -CHO | 0.56 | 0.22 | 0.29 | aldehyde |
| -COCH3 | 0.62 | 0.14 | 0.21 | Me-ketone |
| -COCH2CH3 | 0.63 | 0.13 | 0.20 | |
| -CO-C6H5 | 0.47 | 0.13 | 0.22 | |
| -COOH | 0.85 | 0.18 | 0.25 | acid |
| -COOCH3 | 0.71 | 0.11 | 0.21 | Me-ester |
| -COOC6H5 | 0.90 | 0.17 | 0.27 | |
| -CONH2 | 0.61 | 0.10 | 0.17 | amide |
| -COCl | 0.84 | 0.20 | 0.36 | acid chloride |
| -CN | 0.36 | 0.18 | 0.28 | nitrile |
| -NH2 | -0.75 | -0.25 | -0.65 | amino |
| -NH(CH3) | -0.80 | -0.22 | -0.68 | Me-amine |
| -N(CH3)2 | -0.66 | -0.18 | -0.67 | Di-Me-amine |
| -N(CH3)3+I- | 0.69 | 0.36 | 0.31 | Ammonium |
| -NHCOCH3 | 0.12 | -0.07 | -0.28 | Amido |
| -NO | 0.58 | 0.31 | 0.37 | nitroso |
| -NO2 | 0.95 | 0.26 | 0.38 | nitro |
| -SH | -0.08 | -0.16 | -0.22 | thiol |
| -SCH3 | -0.08 | -0.10 | -0.24 | Me-thioether |
| -SC6H5 | 0.06 | -0.09 | -0.15 | |
| -SO2OH | 0.64 | 0.26 | 0.36 | sulfon |
| SO2NH2 | 0.66 | 0.26 | 0.36 | sulfonamide |
| -OH | -0.56 | -0.12 | -0.45 | phenol |
| -OCH3 | -0.48 | -0.09 | -0.44 | Me-ether |
| -OCH2CH3 | -0.46 | -0.10 | -0.43 | |
| -OC6H5 | -0.29 | -0.05 | -0.23 | |
| -OOCCH3 | -0.25 | 0.03 | -0.13 | acetate |
| -OOCC6H5 | -0.09 | 0.09 | -0.08 | benzoate |
| -F | -0.26 | 0.00 | -0.20 | fluoro- |
| -Cl | 0.03 | -0.02 | -0.09 | chloro- |
| -Br | 0.18 | -0.08 | -0.04 | bromo- |
| -I | 0.39 | -0.21 | -0.03 | iodo- |
Example: 1-Chloro-4-nitrobenzol
