What absorbs at 1350 cm⁻¹ in an FTIR spectrum?
A band near 1350 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 1350 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 | 20 | 18 | 1.0 |
| Amide | 10 | 10 | 1.0 |
| Acetate | 7 | 7 | 1.0 |
| Secondary amine | 7 | 7 | 1.0 |
| C n single bond | 7 | 7 | 1.0 |
| Methoxy (OCH3) | 6 | 6 | 1.0 |
| Methacrylate | 6 | 6 | 1.0 |
| C-O single bond | 6 | 6 | 1.0 |
| N-O bond | 6 | 5 | 1.0 |
| Aromatic ring | 4 | 4 | 1.0 |
| Carboxyl (COOH) | 4 | 4 | 1.0 |
| C c single bond | 4 | 4 | 1.0 |
| Hydroxyl (O-H) | 3 | 3 | 1.0 |
| N h | 3 | 3 | 1.0 |
| Nitrate | 3 | 2 | 1.0 |
| Ester | 2 | 2 | 1.0 |
| Nitrogen heterocycle | 2 | 1 | 1.0 |
| Carbonyl (C=O) | 1 | 1 | 1.0 |
| Water (H2O) | 1 | 1 | 1.0 |
| Phosphorus | 1 | 1 | 1.0 |
| Phosphate (PO4) | 1 | 1 | 1.0 |
| C=n | 1 | 1 | 1.0 |
| Alkene (C=C) | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Boron nitrogen | 1 | 1 | 1.0 |
| S eq o | 1 | 1 | 1.0 |
| Imide | 1 | 1 | 1.0 |
| Carbonate | 1 | 1 | 1.0 |
| Carbohydrate | 1 | 1 | 1.0 |
| Fluorine (C-F) | 1 | 1 | 0.9 |
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 |
|---|---|---|---|
| STARCH | 1350, 1650, 1540 | Acetate, Alkyl C-H, Amide | 1 |
| nanotube | 1350, 1540, 1080 | Amide, Acetate, Alkyl C-H | 1 |
| bacterial cellulose | 1350, 1050, 1631 | Alkyl C-H, Acetate, 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 1350 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
-
Acetate confidence 1.0
“Characteristic peaks were observed at cm-1 cm-1 1350 (C-O stretching) and 950 (C-O-C bending).”
Felipe Tirado 等 - 2017 - EVALUATION OF THE COAGULANT CAPACITY OF STARCH OBT DOI: 10.20937/RICA.2017.33.esp01.11 -
N-O bond confidence 1.0
“cm-1 bands located ~1350 and 1556 No peak corresponding to G band of 1600 graphitic phase was observed in the Raman spectra.”
Gupta 和 Rahini - 2017 - Electrochemical synthesis and characterization of DOI: 10.1016/j.electacta.2017.10.079 -
Carboxyl (COOH) confidence 1.0
“From 1500 to also to the asymmetric carboxylate band and/or CH deformation 2 band.Below1350cm-1,thesepeaksmightbeusedasafingerprint of GBP.”
Hsu 和 Lin - 2009 - Rapid examination of the kinetic process of intram DOI: 10.1016/j.tca.2008.12.008 -
Carbohydrate confidence 1.0
“the band at 1650 cm(cid:1)1 OeCeH, g-irradiated maize starch granules were was attributed to the bent modes of band at 1350 Unirradiated and”
Modifications of structure and physicochemical properties of maize starch by γ-irradiation treatments DOI: 10.1016/j.lwt.2011.10.012 -
Amide confidence 1.0
“Peak Assignment of PAL and the Stretching According to the Spectrum of the PAL Casting Film in Figure 1 and the Spectrum of the Si Substrate in Figure 2 (cm-1) peak position assignment N-H 3348 asym stretching of NH2 ((cid:238)) N-H 3200 sy”
Lu 和 Mi - 2005 - Characterization of the interfacial interaction be DOI: 10.1021/ma0486896 -
Amide confidence 1.0
“The carbonyl transmission peak at treated in 0.1 M NaOH at 80 for 20 min to remove any remaincm-1 1350cm-1 C-N 1700 ing microorganisms, medium component and soluble polysaccharand stretching peak at of chemically purified modified ide.”
Covalently grafted carbon nanotube on bacterial cellulose composite for flexible touch screen application DOI: 10.1016/j.matlet.2013.05.126 -
Carbonate confidence 1.0
“The broad band at 1350 is due to carbonate cm-1 cm-1 at 1422 is assigned to C-H bending of -CH in PVA present in the atmosphere.”
Synthesis, Structural, Optical, Electrical and Thermal Studies of Poly(vinyl alcohol)/CdO Nanocomposite Films DOI: 10.1007/s10904-017-0662-1 -
Hydroxyl (O-H) confidence 1.0
“The peaks found in between 1350cm-1 1390 and 3475-3530 are assigned OH-bending and OH-stretching modes of vibrations.”
Srinivasan - 2019 - Morphological and Optical Properties of Cu1-xZnxO DOI: 10.1134/S1027451019060508
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