What absorbs at 2960 cm⁻¹ in an FTIR spectrum?
A band near 2960 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 2960 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 | 63 | 52 | 1.0 |
| Methyl | 20 | 14 | 1.0 |
| Methoxy (OCH3) | 11 | 8 | 1.0 |
| Methacrylate | 10 | 7 | 1.0 |
| Acetate | 10 | 7 | 1.0 |
| Hydroxyl (O-H) | 6 | 6 | 1.0 |
| Alkene (C=C) | 5 | 5 | 1.0 |
| C c single bond | 3 | 3 | 1.0 |
| Hydrogen bond | 3 | 3 | 1.0 |
| Protein | 2 | 2 | 1.0 |
| Aromatic ring | 2 | 2 | 1.0 |
| N h | 2 | 2 | 1.0 |
| Aldehyde (CHO) | 1 | 1 | 1.0 |
| Sulfate (SO4) | 1 | 1 | 1.0 |
| C-O single bond | 1 | 1 | 1.0 |
| Silicon carbon | 1 | 1 | 1.0 |
| Phosphate (PO4) | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Phospholipid | 1 | 1 | 1.0 |
| Water (H2O) | 1 | 1 | 1.0 |
| Amide | 1 | 1 | 1.0 |
| Secondary amine | 1 | 1 | 1.0 |
| Boron nitrogen | 1 | 1 | 1.0 |
| Silanol (Si-OH) | 1 | 1 | 1.0 |
| Lipid | 1 | 1 | 0.8 |
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 |
|---|---|---|---|
| silica | 2960, 1100, 1080 | Alkyl C-H, Methacrylate | 1 |
| polypropylene | 2960, 1030, 1600 | Alkyl C-H, Methacrylate, 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 2960 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
-
Alkyl C-H confidence 1.0
“772 O-C-Odeformation tionmodes.Forthematerialunderstudytheasymmetricstretching COOscissoring 649 2960cm-1 mode of the methylene group is observed at around in”
Caroline 等 - 2009 - Growth, optical, thermal and dielectric studies of DOI: 10.1016/j.matchemphys.2008.09.070 -
Alkyl C-H confidence 1.0
“The peak around 2960 cm-1 indicates C-H bonds Although Mg is oxidized rapidly when it is exposed to air or an aqueous solution, its in the CH3 and CH2 groups and was seen in samples modified with PAMAM, APTES, and oxidation is largely preve”
Surface Heparinization of a Magnesium-Based Alloy: A Comparison Study of Aminopropyltriethoxysilane (APTES) and Polyamidoamine (PAMAM) Dendrimers DOI: 10.3390/jfb13040296 -
Alkyl C-H confidence 1.0
“The first hypothesis 2960cm-1 arise from the wetting measurements (Table 2), which confirm is reasonable since the band at (due to CH species) 3 the absence of the -COOH terminus on the PS surface since a can be assigned to the methyl of th”
Giovannozzi 和 Rocchia - 2008 - Effect of the reaction time, reagent concentration DOI: 10.1016/j.snb.2007.10.043 -
C c single bond confidence 1.0
“Hence, we focused on IR bands originating C\H C_C from the aliphatic and the aromatic bands as being the orcm-1asarepresentaganiccomponents.Wechosethebandat2960 4.2.”
FTIR microspectroscopy of Ediacaran phosphatized microfossils from the Doushantuo Formation, Weng'an, South China DOI: 10.1016/j.gr.2013.05.002 -
Alkyl C-H confidence 1.0
“(cm-1) (cm-1) (cm-1) asymmetric stretching lipids 2927 37.49 ± 0.79 2921 51.48 ± 0.94 2925 72.88 ± 1.25 CH 2 asymmetric stretching Lipids 2960 52.59 ± 0.64 2954 39.48 ± 1.74 2963 23.18 ± 0.96 CH”
Spectral profile index changes as biomarker of toxicity in Catla catla (Hamilton, 1822) edible fish studied using FTIR and principle component analysis DOI: 10.1007/s42452-020-3001-z -
Hydroxyl (O-H) confidence 1.0
“Pt/silicaa (cid:2)2840 Perturbed O-H stretch of Si-OH-NH 2960 3000 2900 3 (broadband feature)”
Leewis 等 - 2006 - Ammonia adsorption and decomposition on silica sup DOI: 10.1016/j.apsusc.2005.12.115 -
Alkyl C-H confidence 1.0
“2920cm(cid:3)1 The peaks at 2960 and are assigned to the CH or”
Synergistic effects of ferric pyrophosphate (FePP) in intumescent flameretardant polypropylene DOI: 10.1002/pat.1590 -
Alkyl C-H confidence 1.0
“Moreover, the peak at about 2960 is related to the asymmetric stretching mode of the CH groups of both protein and lipid components.”
Classification of Healthy and Cancer Colon Cells Grown on Glass Coverslip by Means of Fourier Transform Infrared Spectroscopy and Multivariate Methods DOI: 10.3390/photonics10040481
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