Table 2.
Functional groups and modes of vibration in ethanolic and aqueous extracts.
| Wavenumber (cm−1) | Functional group | Vibration mode |
|---|---|---|
| 3292 | O–H | Stretching (sym) |
| 2929 and 2852 | −C–H (CH2) | Asymmetric & symmetric stretching vibration of methylene (−CH2) group |
| 2852 | −C–H (CHO) | Stretching (sym) |
| 1734 | C‗O (CHO, COOCH3) | Carbonyl (C‗O) functional group from the ester linkage & aldehyde |
| 1612 | N–H (NH2), C‗C (alkene) | Bending, stretching |
| 1514 | N‗O (NO2), C‗C (aromatic) | Stretching |
| 1416 | −C–H (CH3) | Bending |
| 1368 | S‗O (SO2), C–X, N‗O (NO2) | Stretching |
| 1273–1043 | C–X, S‗O (SO2), C–N (NH2), C–O (OH, COOH) | Stretching |
| 924 | −C–H (alkene) | Bending & out of plane vibration |
| 819 | −C–H (aromatic) | bending & out of plane vibration |
| 779–540 | C–X (halogen) | Vibration of halogen & out of plane vibration of disubstituted aromatics |