What absorbs at 2952 cm⁻¹ in an FTIR spectrum?
A band near 2952 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 2952 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 | 11 | 10 | 1.0 |
| Methacrylate | 3 | 3 | 1.0 |
| Acetate | 3 | 3 | 1.0 |
| Methyl | 2 | 2 | 1.0 |
| Methoxy (OCH3) | 2 | 2 | 1.0 |
| Ketone | 1 | 1 | 1.0 |
| Ester | 1 | 1 | 1.0 |
| Carboxyl (COOH) | 1 | 1 | 1.0 |
| Carbonyl (C=O) | 1 | 1 | 1.0 |
| Amide | 1 | 1 | 1.0 |
| Hydroxyl (O-H) | 1 | 1 | 1.0 |
| Silicon (Si) | 1 | 1 | 1.0 |
| Aromatic ring | 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 |
|---|---|---|---|
| polypropylene | 2952, 1030, 1600 | Alkyl C-H, Methacrylate, Acetate | 1 |
| cotton fabric | 2952, 900, 862 | Alkyl C-H, Methacrylate, Acetate | 1 |
| microplastics | 2952, 1643, 1614 | Alkyl C-H, Methacrylate, Acetate | 1 |
| quercetin | 2952, 1745, 1612 | Methacrylate, Acetate, Alkyl C-H | 1 |
| dentin | 2952, 575, 1740 | Methacrylate, Acetate, 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 2952 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
“The PP showed reference peaks displayed at 972, 997, and 1165 cm-1 (-CH3 oscillating 3 -1 -1 oscillating vibrations), 1375 cm (-CH symmetric bending vibrations), 2952 cm (-CH”
Campanale 等 - 2023 - Fourier Transform Infrared Spectroscopy to Assess DOI: 10.3390/polym15040911 -
Silicon (Si) confidence 1.0
“accepted 13 November 2012 cm-1 Abstract: A new strategy to improve silicon-based endodontic corresponding to the stretching (peaks at 2952 and 2923 CAH treatment tightness by dentine hydrophobization is presented of bonds) and by the increa”
Root canal hydrophobization by dentinal silanization: Improvement of siliconbased endodontic treatment tightness DOI: 10.1002/jbm.b.32874 -
Hydroxyl (O-H) confidence 1.0
“In the FTIR spectrum of Ma, there were absorbance of O-H stretching at 3418 cm-1 cm-1, to 2952 and C=O stretching of carboxylic acid”
Setyawan 等 - 2018 - Improvement in vitro Dissolution Rate of Quercetin DOI: 10.22146/ijc.28511 -
Alkyl C-H confidence 1.0
“The C-H stretching band shifted to a higher wavenumber at 2952 cm-1, indicating changes in the β-1,4-glycosidic linkage torsion angle [48].”
Impact of NaOH Concentration on Deweaving of Cotton Fabric in Aqueous Solutions DOI: 10.3390/su13042015 -
Alkyl C-H confidence 1.0
“cm-1 at 1735 corresponds to the bond stretching vibrations of the carboxyl groups (C=O) and a set of bands at 2952 to cm-1 2852 is associated with the stretching vibrations of the bond between the aliphatic carbon and hydrogen (C-H).”
Cesconeto 等 - 2017 - Evaluation of a Thermochromic Liquid Crystal for U DOI: 10.1590/1980-5373-MR-2016-0717 -
Alkyl C-H confidence 1.0
“Strong band at 2952 to aldehydic C-H stretching (Sharma et al.”
Characterization, cytotoxicity, and genotoxicity properties of novel biomediated nanosized-silver by Egyptian Streptomyces roseolus for safe antimicrobial applications DOI: 10.1007/s11274-022-03231-6 -
Acetate confidence 1.0
“related to the asymmetric elongation vibration -CH at 2952 (ii) bands related to 3 related to the asymmetric elongation vibration -CH3 at 2952 cm-1;”
Simultaneous Treatment of Both Sides of the Polymer with a Conical-Shaped Atmospheric Pressure Plasma Jet DOI: 10.3390/polym15020461 -
Alkyl C-H confidence 1.0
“-CH 3-C-H asymmetric stretching vibration absorption peak was at 2952 The stretch-”
Fabrication and Performance of Phase Change Thermoregulated Fiber from Bicomponent Melt Spinning DOI: 10.3390/polym14091895
Have a spectrum with this band?
Upload your FTIR spectrum and get a full interpretation report — peak assignments with literature citations, library matches, and a literature-backed analysis — in seconds.