What absorbs at 1427 cm⁻¹ in an FTIR spectrum?
A band near 1427 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 1427 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 |
|---|---|---|---|
| Alkyl C-H | 17 | 16 | 1.0 |
| Hydroxyl (O-H) | 6 | 6 | 1.0 |
| Aromatic ring | 5 | 4 | 1.0 |
| Secondary amine | 4 | 3 | 1.0 |
| C n single bond | 4 | 3 | 1.0 |
| Amide | 4 | 3 | 1.0 |
| Methoxy (OCH3) | 4 | 3 | 1.0 |
| Methacrylate | 4 | 3 | 1.0 |
| C-O single bond | 4 | 3 | 1.0 |
| Acetate | 4 | 3 | 1.0 |
| Carboxyl (COOH) | 3 | 3 | 1.0 |
| Carbonate | 2 | 2 | 1.0 |
| Carbohydrate | 2 | 2 | 1.0 |
| Fatty acid | 2 | 2 | 1.0 |
| C c single bond | 2 | 1 | 1.0 |
| Silicon (Si) | 1 | 1 | 1.0 |
| Metal oxygen | 1 | 1 | 1.0 |
| Water (H2O) | 1 | 1 | 1.0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1.0 |
| Methyl | 1 | 1 | 1.0 |
| Amino acid | 1 | 1 | 1.0 |
| N h | 1 | 1 | 1.0 |
| Chlorine | 1 | 1 | 1.0 |
| Chitosan | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Acetyl | 1 | 1 | 1.0 |
| Lignin | 1 | 1 | 1.0 |
| Carbonyl (C=O) | 1 | 1 | 0.9 |
| Nitrogen heterocycle | 1 | 0 | 1.0 |
| Alkene (C=C) | 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 |
|---|---|---|---|
| cellulose | 1427, 1735, 1650 | Alkyl C-H, Hydroxyl (O-H) | 1 |
| PVC | 1427, 834, 1195 | Alkyl C-H, Hydroxyl (O-H) | 1 |
| nanocellulose | 1427, 1540, 1646 | Alkyl C-H, Hydroxyl (O-H) | 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 1427 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
-
Aromatic ring confidence 1.0
“cm-1 characteristic peak at 1735 (acetyl groups in xylan and other nonconjugated carcm-1 cm-1 bonyls), C=O stretch in xylan (hemicelluloses) and the peaks at 1508 and 1427 cm-1 cm-1 show the aromatic skeletal vibration of lignin.”
n-Heptadecane-Impregnated Wood as a Potential Material for Energy-Saving Buildings DOI: 10.3390/f13122137 -
Alkyl C-H confidence 1.0
“groups in xylan and other non-conjugated carbonyls, a C = O stretch in xylan (hemicellucm-1, loses), a lignin aromatic skeletal vibration at 1508 a lignin aromatic skeletal vibration cm-1 cm-1, cm-1 at 1427 with a C-H deformation at 1365 an”
Can 等 - 2023 - Choline Chloride-Based Deep Eutectic Solvent-Treat DOI: 10.3390/f14030569 -
Alkyl C-H confidence 1.0
“Certain low magnitude peaks cm-1 like the one at 1427 correspond to CH bending vibrations also likewise exhibit a decrease in its”
Daniel 等 - 2020 - Citric acid modified cellulose a cost effective a DOI: 10.1080/15567036.2020.1773963 -
Alkyl C-H confidence 1.0
“cm-1, cm-1, cm-1 The absorption bands around 1427 1315 and 1029 correspond to the scissoring, stretching, bending vibrations of -CH 2, -CH, -OH, and C-O bonds in cellulose.”
Lapuz 等 - 2022 - Production of Nanocellulose Film from Abaca Fibers DOI: 10.3390/cryst12050601 -
Alkyl C-H confidence 1.0
“The absorption bands at around 1427 the C-H wagging and bending vibration [12].”
Understanding Hydrothermal Dechlorination of PVC by Focusing on the Operating Conditions and Hydrochar Characteristics DOI: 10.3390/app7030256 -
Hydroxyl (O-H) confidence 1.0
“Summary of molecular vibration of PBS chromophore (cm-1) Group Wavenumber, 𝝂 700 C-H bending 754 C-H bending of 776 C-H bending 1079 S=O stretching Pre-pro 1218 C-N stretching 1289 C-N stretching 1330 S=O stretching 1402 S=O stretching 1427”
Power-Dependent Nonlinear Optical Behaviours of Ponceau BS Chromophore at 532 nm via Z-Scan Technique DOI: 10.1016/j.jphotochem.2020.112574 -
Alkyl C-H confidence 1.0
“The peaks at cm-1 1427, 1092, 1377 and 852 are appeared due to C-H”
Structural and electrical behaviours of amino acid-based solid polymer electrolytes DOI: 10.1007/s12034-021-02464-9 -
Acetate confidence 1.0
“The absorbance band at the 1427 belt with a constant speed over an area illuminated by a C-O C-H indicate vibrations or deformation in the samples laser beam [23] or by the free-falling method [24].”
Awad 等 - 2023 - An attempt to apply laser combustion to palm waste DOI: 10.1051/jeos/2023003
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