What absorbs at 1221 cm⁻¹ in an FTIR spectrum?
A band near 1221 cm⁻¹ can point to several functional groups. Below are the most likely assignments, ranked by how much published evidence supports each — every one traceable to literature (DOI) and cross-validated against our 130,000+ reference spectra and knowledge graph.
Backed by 8 cited sources
Possible functional-group assignments
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| C-O single bond | 5 | 5 | 1.0 |
| Amide | 4 | 4 | 1.0 |
| Methoxy (OCH3) | 4 | 4 | 1.0 |
| Methacrylate | 4 | 4 | 1.0 |
| Acetate | 4 | 4 | 1.0 |
| Secondary amine | 2 | 2 | 1.0 |
| C n single bond | 2 | 2 | 1.0 |
| Phosphate (PO4) | 2 | 2 | 1.0 |
| Hydroxyl (O-H) | 2 | 2 | 1.0 |
| Phosphorus | 1 | 1 | 1.0 |
| Aromatic ring | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Chlorine | 1 | 1 | 1.0 |
| Urethane | 1 | 1 | 1.0 |
| N h | 1 | 1 | 1.0 |
| Metal oxygen | 1 | 1 | 1.0 |
| Fluorine (C-F) | 1 | 1 | 0.7 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Literature behind these assignments
-
confidence 1.0
“Explicit assignment in text.”
A facile synthesis of ZSM-11 zeolite particles using rice husk ash as silica source DOI: 10.1016/j.matlet.2012.07.079 -
Metal oxygen confidence 1.0
“cm-1) ν 42-), pattern, three intense bands are observed in the 54 (<100 allowing the observation of (SO 75 2 significantly antisymmetric stretching region at 1221, 1134 and 55 Fe-O, H 2O and lattice modes, which overlap 76 cm-1.”
Ventruti 等 - 2016 - Hydrogen bond system and vibrational spectroscopy DOI: 10.1127/ejm/2016/0028-2571 -
Amide confidence 1.0
“Bands depicting amide II were found at 1517, cm-1, 1586, 1514, and 1522 whereas amide III bands were registered at 1221, 1219, 1227,”
Comparison of Different Methods for Spongin-like Collagen Extraction from Marine Sponges (Chondrilla caribensis and Aplysina fulva): Physicochemical Properties and In Vitro Biological Analysis DOI: 10.3390/membranes11070522 -
Phosphate (PO4) confidence 1.0
“Indeed, P-O-C observed at, respectively, 1030 and 1221cm-1 new peak appeared at and could be attributed to the stretching vibration of P=O.”
Dardouri 等 - 2015 - Aminoalkylated Merrifield Resins Reticulated by Tr DOI: 10.1155/2015/782841 -
confidence 1.0
“There are three important vibrations of collagen molecules: at 1644 ν(C=O) (amide I), 1541 cm-1 attributed to δ(N-H) and ν(C-N) (amide II) and at 1221 cm-1 cm-1 cm-1 ν(C=O) ν(C=O) (amide I), 1541 cm-1 attributed to δ(N-H) and ν(C-N) (amide”
Drobota 等 - 2020 - Preparation and Characterization of Electrospun Co DOI: 10.3390/ma13183961 -
C-O single bond confidence 1.0
“Published cm(cid:3)1,35,39 cm(cid:3)1 band).35,38 presence of a covalent CH vibrations at 1459, 1368, and 1309 amide I (ester The peak at 1531 shows 2 cm(cid:3)1,35,38 cm(cid:3)1,35 is C-O-C band) at 1221 that the urethane band increases wi”
Polyurethane/58S bioglass nanofibers: synthesis, characterization, and in vitro evaluation DOI: 10.1039/c5ra24786a -
confidence 1.0
“2.24 - 2.58 (m, 2 H, 4) 2.61 - 2.95 (m, 2 H, 3) 3.61 (ddt, C-O carboxylic acids 1188 J=2.33, 1.58, 0.75, 0.75 Hz, 2 H, 6) 4.44 - 4.46 (s, 1 Methylene twist 1298, 1275 H,10) 6.57 (d, J=5.10 Hz, 1 H, 7) 6.97 (td, J=7.50, 1.20 Chlorophenyl C-C”
Housheh 等 - 2015 - GCMS, FTIR and NMR Studies for the Identification DOI: 10.5530/ijper.49.4.1 -
Hydroxyl (O-H) confidence 1.0
“1221cm-1 cm-1 and 1104 CO stretch corresponding to the alcohol group (Jaganathan et al.”
Jaganathan 等 - 2019 - Blood compatibility assessments of electrospun pol DOI: 10.1590/0001-3765201920190018
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