What absorbs at 1300 cm⁻¹ in an FTIR spectrum?
A band near 1300 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 1300 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 | 24 | 23 | 1.0 |
| C-O single bond | 22 | 21 | 1.0 |
| Methoxy (OCH3) | 19 | 18 | 1.0 |
| Methacrylate | 19 | 18 | 1.0 |
| Acetate | 19 | 18 | 1.0 |
| Amide | 17 | 15 | 1.0 |
| Secondary amine | 9 | 8 | 1.0 |
| C n single bond | 9 | 8 | 1.0 |
| C c single bond | 8 | 8 | 1.0 |
| Phosphate (PO4) | 6 | 6 | 1.0 |
| Ester | 6 | 5 | 1.0 |
| Hydroxyl (O-H) | 5 | 5 | 1.0 |
| Water (H2O) | 5 | 5 | 1.0 |
| Aromatic ring | 5 | 4 | 1.0 |
| Carboxyl (COOH) | 5 | 4 | 1.0 |
| Alkene (C=C) | 5 | 4 | 1.0 |
| N h | 4 | 4 | 1.0 |
| Nucleic acid | 4 | 4 | 1.0 |
| Phosphorus | 4 | 4 | 1.0 |
| Silicon (Si) | 3 | 3 | 1.0 |
| Ring structure | 3 | 3 | 1.0 |
| Silicon carbon | 2 | 2 | 1.0 |
| Nitrogen heterocycle | 2 | 2 | 1.0 |
| Methyl | 2 | 2 | 1.0 |
| Metal oxygen | 2 | 2 | 1.0 |
| C=n | 2 | 1 | 1.0 |
| Silicon nitrogen | 1 | 1 | 1.0 |
| S eq o | 1 | 1 | 1.0 |
| Phospholipid | 1 | 1 | 1.0 |
| Carbonate | 1 | 1 | 1.0 |
| Fatty acid | 1 | 1 | 1.0 |
| Amine primary | 1 | 1 | 1.0 |
| Carbon dioxide | 1 | 1 | 1.0 |
| Metal hydroxyl | 1 | 1 | 1.0 |
| Oxygen heterocycle | 1 | 1 | 1.0 |
| Carbonyl (C=O) | 1 | 1 | 0.8 |
| Silicate | 1 | 1 | 0.7 |
| Carbohydrate | 1 | 1 | 0.7 |
| Nitrate | 1 | 0 | 1.0 |
| Bromine | 1 | 0 | 1.0 |
| Fluorine (C-F) | 1 | 0 | 0.5 |
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 |
|---|---|---|---|
| alginate | 1300, 1100, 1715 | Methacrylate, Alkyl C-H, Methoxy (OCH3) | 1 |
| polysaccharide | 1300, 1637, 1320 | Methacrylate, Alkyl C-H, C-O single bond | 1 |
| polyaniline | 1300, 1565, 1570 | Alkyl C-H, Methacrylate | 1 |
| PANI | 1300, 2930, 1136 | Alkyl C-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 1300 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
-
Oxygen heterocycle confidence 1.0
“The cm(cid:3)1intheC-matandcomposite lackofamajorpeakaround1300 indicatesthat the DWNTstarted with few defects and the curingof the epoxy did not damage them.”
Probing deformation of double-walled carbon nanotube (DWNT)/epoxy composites using FTIR and Raman techniques DOI: 10.1016/j.compscitech.2010.04.025 -
Silicon (Si) confidence 1.0
“Finally, absorption bands between 1300 and are assigned to the combination of stretch and bend vibrations of Si”
Cai 等 - 2007 - A Fourier transform infrared spectroscopic study o DOI: 10.1016/j.saa.2006.02.053 -
Amide confidence 1.0
“The intensity of cm-1 cm-1 silk-RGO-PANI characteristic absorption peaks at 1300 and 798 for C-N stretching vibrations and the”
Highly conductive and flexible silk fabric via electrostatic self assemble between reduced graphene oxide and polyaniline DOI: 10.1016/j.orgel.2017.12.016 -
Aromatic ring confidence 1.0
“The peaks at 1568 and 1468cm(cid:1)1 CQC 76 10 are attributed to stretching of the quiniod and 1250cm(cid:1)1 77 11 benzenoid rings, the peaks at 1300 and are assigned to”
Effect of ultrasonication on particle size and magnetic properties of polyaniline NiCoFe2O4 nanocomposites DOI: 10.1016/j.jmmm.2014.04.024 -
Carboxyl (COOH) confidence 1.0
“Both the asymmetric (1700~1600 cm-1) and symcarboxyl anions exhibited characteristic peaks, indicating the presence of carboxyl groups metric (1400~1300 cm-1) stretching of carboxyl anions exhibited characteristic peaks, indiand uronic acid”
Formation Optimization, Characterization and Antioxidant Activity of Auricularia auricula-judae Polysaccharide Nanoparticles Obtained via Antisolvent Precipitation DOI: 10.3390/molecules27207037 -
Hydroxyl (O-H) confidence 1.0
“[41], and stretching O-H group [42], respectively were Another significant peak was observed between 1300 to observed.”
Enhancing proton conductivity of sodium alginate doped with glycolic acid in bio-based polymer electrolytes system DOI: 10.1007/s10965-020-02142-0 -
Acetate confidence 1.0
“PZC carbons is the presence of overlapping bands between 1300 and that surface maintains basic characteristic within the typical pH cm-1, C-O O-H 1000 which can be assigned to stretching and range (from 5.5 to 9.5 pH units) of surface water”
Iriarte-Velasco 等 - 2008 - Natural Organic Matter Adsorption onto Granular Ac DOI: 10.1021/ie800912y -
Alkene (C=C) confidence 1.0
“1680-1600 C=C stretching (alkenes) 1600-1500 C=C stretching (aromatics) 1300 C-O-C stretching (ethers)”
Kopczynski 等 - 2015 - THERMOGRAVIMETRIC AND KINETIC ANALYSIS OF RAW AND DOI: 10.1515/cpe-2015-0014
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