What absorbs at 1122 cm⁻¹ in an FTIR spectrum?
A band near 1122 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 1122 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.
Possible functional-group assignments
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| Methoxy (OCH3) | 6 | 5 | 1.0 |
| Methacrylate | 6 | 5 | 1.0 |
| Acetate | 6 | 5 | 1.0 |
| C-O single bond | 5 | 4 | 1.0 |
| Carbohydrate | 4 | 4 | 1.0 |
| Alkyl C-H | 4 | 4 | 1.0 |
| Phosphate (PO4) | 3 | 3 | 1.0 |
| Amide | 3 | 3 | 1.0 |
| C c single bond | 3 | 3 | 1.0 |
| Carboxyl (COOH) | 2 | 2 | 1.0 |
| Hydroxyl (O-H) | 2 | 2 | 1.0 |
| Aromatic ring | 2 | 2 | 1.0 |
| Siloxane (Si-O-Si) | 2 | 1 | 1.0 |
| Silicon-oxygen (Si-O) | 2 | 1 | 1.0 |
| Nucleic acid | 1 | 1 | 1.0 |
| N-O bond | 1 | 1 | 1.0 |
| Hydrogen bond | 1 | 1 | 1.0 |
| Silicon (Si) | 1 | 1 | 1.0 |
| Metal oxygen | 1 | 1 | 1.0 |
| Nitrate | 1 | 1 | 1.0 |
| Carbonyl (C=O) | 1 | 1 | 1.0 |
| Methyl | 1 | 1 | 1.0 |
| Secondary amine | 1 | 1 | 1.0 |
| C n single bond | 1 | 1 | 1.0 |
| N h | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Lignin | 1 | 1 | 1.0 |
| Ester | 1 | 0 | 1.0 |
Ranking reflects accumulated literature evidence, not a single fixed rule. Always confirm against your sample context.
Possible materials
| Material | Supporting peaks | Overlapping groups | Cited sources |
|---|---|---|---|
| glucose | 1122, 1740, 1400 | C-O single bond, Methacrylate, Acetate | 1 |
| polymer | 1122, 1718, 1722 | Methacrylate, Acetate, C-O single bond | 1 |
| lignin | 1122, 1035, 1510 | Methacrylate, Acetate, C-O single bond | 1 |
| wood | 1122, 1740, 1730 | Methacrylate, Acetate, Methoxy (OCH3) | 1 |
| polyaniline | 1122, 1565, 1570 | Methacrylate, Acetate | 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 1122 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.
Literature behind these assignments
-
C c single bond confidence 1.0
“The peak assignments are: 1122 (C-C cm21 cm21 stretch), 1115 (C-C stretch), 1100 (Si-O cm21 stretch of clay), 1082 (Si-O stretch of clay and”
Loo 和 Gleason - 2004 - Investigation of polymer and nanoclay orientation DOI: 10.1016/j.polymer.2004.06.025 -
confidence 1.0
“At 50K, 1122cm-1 insiliconhaveeitherahighlysymmetricshapesuchasspheranother peak attributed to interstitial oxygen at”
Ma 等 - 2005 - Infrared studies of the oxygen precipitation in fa DOI: 10.1016/j.mseb.2005.06.005 -
Alkyl C-H confidence 1.0
“The peak appeared at 1122 corresponds to asymmetrical and symmetrical bending vibration of C-H group [89].”
Majid 等 - 2020 - Effect of Hydrothermal Reaction Time on Electrical DOI: 10.1515/zpch-2019-1423 -
C c single bond confidence 1.0
“and C-N and C-C stretching (1122 cm-1 The band located at 1239 is assigned to the asymmetric PO stretching from phosphodiester”
Mostaco-Guidolin 等 - 2010 - Molecular and chemical characterization by Fourier DOI: 10.3233/SPE-2010-0466 -
Lignin confidence 1.0
“In beech, the peak as a lignin reference since it arises purely due to arocm-1 band at 1122 arises from C-H in plane deformation matic skeletal vibration (C=C) in lignin.”
Pandey 和 Pitman - 2003 - FTIR studies of the changes in wood chemistry foll DOI: 10.1016/S0964-8305(03)00052-0 -
C c single bond confidence 1.0
“cm-1, cm-1, cm-1, cm-1 cm-1.The 964 810 613 and 489 important absorption peaks 1122 by cm-1 is corresponds to C C stretching vibration of quiniod ring, the stretching at 1556 Downloaded vibration of benzoic rings is found to be a strong ban”
Patil 等 - 2011 - Electrical Conductivity of PolyanilineNiZnO3 Comp DOI: 10.1080/00150193.2011.620836 -
Carboxyl (COOH) confidence 1.0
“In contrast, within the cm-1 cm-1, 1200-950 region, the typical lactate peak was observed at 1122 which was 2nd clearly distinguished in the derivative of the spectra (Figure 2b).”
Nondestructive assessment of tissue engineered cartilage based on biochemical markers in cell culture media: Application of attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy DOI: 10.1039/d1an02351a. -
N h confidence 1.0
“In the binary mixture of amine N-H bending ), 1489 (Aromatic C=C), 1122 cm-1”
Siahi 等 - 2018 - Analytical Investigation of the Possible Chemical DOI: 10.15171/apb.2018.074
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