| Leaves powder | Inhibitor prepared using H2SO4 | Corrosion product | |||
| Frequency (cm−1) | Assignment | Frequency (cm−1) | Assignment | Frequency (cm−1) | Assignment |
| 3281.43 | -OH or N-H Stretch | 3334.5 | O-H Stretch | 3329.84 | O-H Stretch |
| 2917.52 | -C-H Stretch | 1634.65 | C=O Stretch | 1635.23 | C=O Stretch |
| 2849.24 | 1189.41 | C-O or C-H Stretch | 1183.08 | C-O or C-N Stretch | |
| 1625.62 | C=O stretch | 1049.60 | 1048.00 | ||
| 1405.52 | C-H bending |
|
|
|
|
| 1316.22 |
|
|
|
| |
| 1244.02 | C-O or C-N stretch |
|
|
|
|
| 1031.06 |
|
|
|
| |