What absorbs at 1286 cm⁻¹ in an FTIR spectrum?
A band near 1286 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 1286 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) | 4 | 4 | 1.0 |
| Methacrylate | 4 | 4 | 1.0 |
| C-O single bond | 4 | 4 | 1.0 |
| Acetate | 4 | 4 | 1.0 |
| Hydroxyl (O-H) | 2 | 2 | 1.0 |
| Ring structure | 2 | 2 | 1.0 |
| Alkene (C=C) | 1 | 1 | 1.0 |
| Aromatic ring | 1 | 1 | 1.0 |
| Secondary amine | 1 | 1 | 1.0 |
| C n single bond | 1 | 1 | 1.0 |
| Amide | 1 | 1 | 1.0 |
| Water (H2O) | 1 | 1 | 1.0 |
| Phosphate (PO4) | 1 | 1 | 1.0 |
| Alkyl C-H | 1 | 1 | 1.0 |
| C c single bond | 1 | 1 | 1.0 |
| N n bond | 1 | 1 | 1.0 |
| Amine primary | 1 | 1 | 1.0 |
| N h | 1 | 1 | 1.0 |
| Oxalate | 1 | 1 | 1.0 |
| Carbonate | 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 |
|---|---|---|---|
| polydopamine | 1286, 1543, 1707 | Methacrylate, Acetate, 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 1286 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
“cm-1 1380 The weak peak at 1286 was the =C-O-C asymmetric stretching vibration absorption cm-1 peak.”
Li 等 - 2011 - The detection of Cypermethrin on the surface of Ap DOI: 10.4028/www.scientific.net/AMR.287-290.2991 -
Hydroxyl (O-H) confidence 1.0
“In the binary mixture of amine N-H bending ), 1489 (Aromatic C=C), 1122 cm-1 cm-1 methyldopa and monohydrate lactose, the endothermic (C-N stretch), 1286 (R-Alkyl O-H deformation cm-1 peak of drug melting is again missing, indicating a kind”
Siahi 等 - 2018 - Analytical Investigation of the Possible Chemical DOI: 10.15171/apb.2018.074 -
Carbonate confidence 1.0
“At pH 5.1, at least four different oxalate species were found at or near the boehmite/water interface for oxalate surface ((cid:1) (cid:2) coverages ox) ranging from 0.25 to 16.44 At relatively low coverages 2.47), strongly adsorbed inner-s”
Yoon 等 - 2004 - Adsorption of organic matter at mineralwater inte DOI: 10.1016/j.gca.2004.04.025 -
confidence 1.0
“Indeed, OH cm(cid:3)1 cm(cid:3)1, 24 N-H ds 1282 primary amines have two bands of the asymmetric and (1286, 1260, 1190, 1176, 1161 and 1081 licensed C-O-”
High effectiveness of pure polydopamine in extraction of uranium and plutonium from groundwater and seawater DOI: 10.1039/c9ra06392g -
Phosphate (PO4) confidence 1.0
“The (P-O) vibration band at 1286 temperature, only the physisorbed water was removed ν cm-1) shifted towards lower frequencies (1260 in all of from the samples, as was determined from the TGA curves”
Giraldo 和 Carlos Moreno-Pirajan - 2013 - Study on the Adsorption of Heavy Metal Ions from A DOI: 10.1039/b211124c -
confidence 1.0
“Explicit assignment: 'C-N stretching vibrations are shown at 1286 and 1142 cm-1'.”
Liao LePing 等 - 2011 - Preparation and characterization of microcapsule c DOI: 10.1007/s11434-010-4133-0 -
Water (H2O) confidence 1.0
“of the bending mode and a far-IR band associated with a for [C and 1576 and 1171 for 44].71,72 librational motion of sterically hindered water molecules (Figure [C 2MIM][BF Stretching modes of the [BF ] anion cm-1 4b).82 (Figure 5a) are the”
MacMillan 等 - 2012 - Interaction of Water Vapor with the Surfaces of Im DOI: 10.1021/jp305029n -
Ring structure confidence 1.0
“vs 1355 1326 117 1368 1331 70 δCH 1326.5 Ring stretch, 1286.0 vw 1301 1272 36 1316 1280 57 ρNH 1282.5 2”
Structure, Spectra and Photochemistry of 2-Amino-4-Methylthiazole: FTIR Matrix Isolation and Theoretical Studies DOI: 10.3390/molecules27123897
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