| Group assigned to the given band | Wavenumber (cm−1) | Quercetin | Deprotonated quercetin (pH 12) | IronQ |
| O–H stretching vibration of phenol | 3386, 3263 | 3352, 3172 | 3353, 3195 | C=O aryl ketonic stretch | 1664 s | 1637 w, 1739 w (shoulders) | 1617 w, 1682 w, 1731 w (shoulders) | C=C aromatic ring stretching bands | 1604 s, 1560 s, 1516 s, 1448 s, 1407 s | 1592 s, 1504 w, 1436 m | 1569 s, 1479 s, 1414 s | O–H bending of phenols | 1376 s | 1364 w | 1382 w | C–H bonds in aromatic hydrocarbon bending (in-plane) | 1315 s, 1128 s, 1088 s, 1012 s, 932 s | 1308 w (shoulder), 1108 m, 1060 m, 1019 m, 950 w | 1337 w, 1121 w, 1085 s 1024 w, 976 m, 955 w, | C–O stretching of aryl ether (C–O–C) | 1260 s | 1272 s | 1259 s | C–O stretching in phenol | 1196 s | — | — | C–CO–C stretching and bending in ketones | 1164 s | 1168 s | 1162 s | C–H bending of aromatic hydrocarbons (out-of-plane) | 884 s, 864 s, 844 s, 820 s, 795/792 w, 720 s, 676, 632 s, 599 s | 890w, 830/808 w, 768 s, 678 w, 642 s, 588 m | 910 w, 808 s, 739 w, 617 m | Fe–O stretching | — | — | 470 s |
|
|