Wavenumber | Band assignment | EOS-20 mM | 20 mM + 2 N | 20 mM + NS | 20 mM + MT | 20 mM + SA |
---|---|---|---|---|---|---|
750 cm−1 | Naphthalenes | 0.07 ± 0.00 | 0.58 ± 0.04 | 0.11 ± 0.01 | 0.10 ± 0.02 | 0.08 ± 0.01 |
815 cm−1 | Naphthalenes | 0.20 ± 0.00 | 0.66 ± 0.03 | 0.21 ± 0.00 | 0.23 ± 0.02 | 0.22 ± 0.00 |
1329 cm−1 | S ring plus G ring condensed (i.e., G ring substituted in C5) | 0.89 ± 0.04 | 0.73 ± 0.01 | 0.82 ± 0.00 | 0.82 ± 0.01 | 0.83 ± 0.02 |
1665 cm−1 | Conjugated carbonyl | 0.31 ± 0.00 | 0.29 ± 0.01 | 0.41 ± 0.00 | 0.29 ± 0.02 | 0.38 ± 0.00 |
1710 cm−1 | C=O stretching in unconjugated ketones and carboxyl groups | 0.41 ± 0.01 | 0.34 ± 0.01 | 0.45 ± 0.03 | 0.42 ± 0.01 | 0.43 ± 0.01 |
2840 cm−1 | C–H stretching (CH3 and CH2) | 0.37 ± 0.01 | 0.35 ± 0.01 | 0.40 ± 0.00 | 0.44 ± 0.02 | 0.36 ± 0.01 |
2940 cm−1 | C–H stretching (CH3 and CH2) | 0.48 ± 0.01 | 0.41 ± 0.00 | 0.51 ± 0.01 | 0.54 ± 0.01 | 0.48 ± 0.00 |
3460 cm−1 | O–H stretching in aliphatic and phenolic –OH | 0.45 ± 0.01 | 0.41 ± 0.01 | 0.52 ± 0.00 | 0.52 ± 0.01 | 0.46 ± 0.01 |