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
Quick answer
A band near 1221 cm⁻¹ is usually interpreted by checking which functional groups repeatedly co-occur there in the literature, then confirming at least one or two additional peaks in the same sample. This page ranks those assignments by accumulated evidence rather than by a single fixed textbook rule.
可能性のある官能基アサイン
| 官能基 | 裏付け事実 | 引用元 | 最高信頼度 |
|---|---|---|---|
| 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 |
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Possible materials
| 素材 | 補助ピーク | Overlapping groups | 引用元 |
|---|---|---|---|
| PET | 1221, 1408, 800 | Methacrylate, Methoxy (OCH3), C-O single bond | 1 |
| collagen | 1221, 1408, 1660 | Amide, Methacrylate, Methoxy (OCH3) | 1 |
| polyurethane | 1221, 2270, 1700 | Methacrylate, C-O single bond, Methoxy (OCH3) | 1 |
Materials are shown only when the same literature pool supports this band and at least one additional characteristic peak.
Spectrum logic
This band becomes meaningful only when read with its neighboring peaks. In practice, analysts first look at the assignments above, then check whether the same sample also shows other peaks expected for the same structural motif. A lone band near 1221 cm⁻¹ is usually not enough for material identification by itself.
Real-world usage
This type of query is common in polymer identification, unknown plastic screening, QC troubleshooting, recycled-material verification, and literature-backed peak assignment review.
Common mistakes
- Treating one isolated band as proof of a material without checking at least one or two supporting peaks.
- Ignoring overlap: multiple functional groups can contribute near the same wavenumber.
- Skipping validation when additives, blends, oxidation, or contamination may distort the spectrum.
Verification advice
When ambiguity remains, validate the hypothesis with DSC, GC-MS, or TGA, especially for blends, degraded samples, and filled polymers.
これらのアサインの根拠となる文献
-
信頼度 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 信頼度 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 信頼度 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) 信頼度 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 -
信頼度 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 信頼度 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 -
信頼度 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) 信頼度 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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