Table 2.
MAS 13C NMR chemical shifts and attributed functional groups.
| 13C chemical shift (ppm) | Chemical group |
|---|---|
| 11.47 | RCH3 |
| 24.7 | CH3, C in R2CH2 |
| 25.36 | C in R2CH2 |
| 32.94 | C in CH3CO |
| 42.29 | C in RCH2NH2 |
| 46.93 | C in R2CH2 |
| 46.92 | CH3CO, hydroxylamine, oximes, hydroxamic acid |
| 57.43 | C in RCH2OH of C6 carbon of crystalline cellulose |
| 64.57 | C in RCH2OH |
| 72.37 | C2, C3, and C5 of cellulose and hemicellulose and hemicellulose and OCαH2 carbons of lignin |
| 82 | Alkynes and hemicelluloses |
| OCαH2 carbons of lignin | |
| 88.57 | C in RCH2O |
| 104.7991 and 119.3584 | C in alkene |
| 116 and 146 | C1 and C6 associated with aromatic and carbon of double bonds on the side chain |
| 128.8219, 137.0418, 145.2929, and 150.7820 | Alkene and aromatic in lignin and its derivative |
| 131 | Alkene |
| 172 and 176 | Carbonyl in ester and acid and carbonyl |
| 128.8219, 137.0418, 145.2929, | C in alkene |
| 150.7820 | aromatic |
| 167.7981, 170.2550, 171.8323, 172.8332, 177.2010 and 181.4474 | carbonyls in ester and carboxylic acid |