What absorbs at 1357 cm⁻¹ in an FTIR spectrum?
A band near 1357 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 1357 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 |
|---|---|---|---|
| Amide | 7 | 7 | 1.0 |
| Secondary amine | 6 | 6 | 1.0 |
| C n single bond | 6 | 6 | 1.0 |
| Alkyl C-H | 4 | 4 | 1.0 |
| N-O bond | 2 | 2 | 1.0 |
| S eq o | 2 | 2 | 1.0 |
| Alkene (C=C) | 1 | 1 | 1.0 |
| Carboxyl (COOH) | 1 | 1 | 1.0 |
| Hydroxyl (O-H) | 1 | 1 | 1.0 |
| Water (H2O) | 1 | 1 | 1.0 |
| Protein alpha helix | 1 | 1 | 1.0 |
| Fatty acid | 1 | 1 | 1.0 |
| N h | 1 | 1 | 1.0 |
| Aromatic ring | 1 | 1 | 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 |
|---|---|---|---|
| AgNPs | 1357, 1232, 1048 | Alkyl C-H, Amide | 1 |
| coal | 1357, 1600, 3030 | Alkyl C-H | 1 |
| silver nanoparticles | 1357, 1636, 1631 | Alkyl C-H, Amide | 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 1357 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
-
N-O bond confidence 1.0
“3 (cid:2) (cid:3)72%, (cid:2) 33cm-1 3-NO band at 1363 and 1390 at the RH of instead of the single 3-NO band of the cm-1 at 1357 for the initial solid NaNO 3, was observed.”
Lu 等 - 2008 - Molecular events in deliquescence and efflorescenc DOI: 10.1063/1.2973623(cid:5) -
Amide confidence 1.0
“The Peak observed at 1357 corresponds to C-N stretching vibrations of aromatic amines and aliphatic amines (Sanghi and Verma 2009).”
Biogenic silver nanoparticles: efficient and effective antifungal agents DOI: 10.1007/s13204-015-0463-1 -
Alkyl C-H confidence 1.0
“2900 is related to C-H The water bending vibrations peaked at 1639 while the peaks cm-1 cm-1 around 1357 indicate the C-H bending.”
Bacterial nanocellulose from agro-industrial wastes: low-cost and enhanced production by Komagataeibacter saccharivorans MD1 DOI: 10.1038/s41598-020-60315-9 -
Amide confidence 1.0
“AM-3 Compound exhibited characteristic peaks at 2790.07, 1443.55 (C-C stretching vibration of thiophene), 1357.21 (C-N and N-N stretching vibration), 1278.82 (in-plane C-H stretching vibration cm-1,”
Novel Hemocompatible Imine Compounds as Alternatives for Antimicrobial Therapy in Pharmaceutical Application DOI: 10.3390/pr8111476 -
Amide confidence 1.0
“7 (cm-1): FTIR (ATR) ν 3300 (broad, OH aromatic), 3097 and 3055 (aromatic C-H stretch), 2965 and 2870 (aliphatic C-H stretch), 1630 (C=N), 1550, 1525 and 1490 (aromatic C-C stretch), 1357 (C-N stretch), 1270 (=C-OH phenolic), 825 and 720 (C”
Elaboration of new modified electrodes (MEs) by electropolymerization of Cu(II)-Schiff base complexes bearing pyrrole moieties: Application in electroreduction of acetophenone and carbon dioxide DOI: 10.1016/j.eurpolymj.2018.10.016 -
Alkyl C-H confidence 1.0
“The peaks at 1357, 1406, and 1454 are various modes of -CH vibrations (scissoring and wagging).”
Cayirli 等 - 2023 - The effect of liquid grinding aids on the dry fine DOI: 10.37190/ppmp/165854 -
Fatty acid confidence 1.0
“cm-1 1357 and 1361 cm-1 cm-1 cm-1 1260 -1300 1298 for Fatty acids cm-1 for major peaks of for α-helix”
Exosomes isolated from two different cell lines using three different isolation techniques show variation in physical and molecular characteristics DOI: 10.1101/2020.06.06.122952 -
Water (H2O) confidence 1.0
“Although permanent gas the same time, the messy peak around 1357 represents the analysis can provide information about the primary gases generation of water vapor.”
Dong 等 - 2019 - Study on Pyrolysis Characteristics of Coal and Com DOI: 10.1155/2019/1032529
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