What absorbs at 2944 cm⁻¹ in an FTIR spectrum?
A band near 2944 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 2944 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 | 17 | 17 | 1.0 |
| Methoxy (OCH3) | 3 | 3 | 1.0 |
| Methyl | 2 | 2 | 1.0 |
| Methacrylate | 2 | 2 | 1.0 |
| Acetate | 2 | 2 | 1.0 |
| Water (H2O) | 1 | 1 | 1.0 |
| C-O single bond | 1 | 1 | 1.0 |
| N h | 1 | 1 | 1.0 |
| Alkene (C=C) | 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 |
|---|---|---|---|
| SiO2 | 2944, 1739, 699 | Alkyl C-H, Methoxy (OCH3) | 1 |
| Polyvinylpyrrolidone | 2944, 1660, 1700 | Alkyl C-H, Methacrylate | 1 |
| Polyvinyl Alcohol | 2944, 1141, 1640 | Alkyl C-H, Methacrylate | 1 |
| rGO | 2944, 2358, 2930 | Methacrylate, Alkyl C-H, Methoxy (OCH3) | 1 |
| hydrogels | 2944, 3281, 1700 | Methacrylate, Alkyl C-H | 1 |
| Polyurethane | 2944, 2270, 1700 | 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 2944 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
“2 cm-1 The peak at 2944 showed C-H stretching vibrations of PVA (samples F1-F3), while cm-1.”
Study of Polyvinyl Alcohol-SiO2 Nanoparticles Polymeric Membrane in Wastewater Treatment Containing Zinc Ions DOI: 10.3390/polym13111875 -
Alkyl C-H confidence 1.0
“The FTIR spectrum of GW2 showed cm-1 𝜋r2]0.5 D characteristic peaks for C-H stretch at 2944 and C=C t0.5, S 4 ∙ = (6) cm-1 [ aromatic stretch at 1662 and NH stretch of amide at”
Owonubi 等 - 2018 - Characterization and in vitro release kinetics of DOI: 10.1007/s40090-018-0139-2 -
Alkyl C-H confidence 1.0
“cm(cid:1)1 cm(cid:1)1 effect respectively.10 bending, The peaks at 2944 and 2983 ally examined to determine the of composition of (poly04/09/2013 C-H bond.12,21,22 were assigned to the stretching mode of a The mer : bioglass solutions) and”
Ravarian 等 - 2013 - Molecular interactions in coupled PMMA-bioglass hy DOI: 10.1039/c2tb00251e -
Alkene (C=C) confidence 1.0
“the peak of 1655.00 the olefinic C-H out of plane bending vibration at the band of 968.22 cm-1 Furthermore, the peak at 3082.50 corresponds to the =C-H stretching vibrations of both the allyl group and the cm-1 aromatic ring, whereas the ab”
Tan 等 - 2018 - Synthesis and Characterization of Polybenzoxazine DOI: 10.1063/1.5066866 -
Alkyl C-H confidence 1.0
“[35,36] The structures cm-1, of the ionene-clays IC-1-3 were confirmed by FTIR spectra, which showed bands at 2944 cm-1, corresponding to the alkyl C-H stretch, and at 3022 corresponding to the methylene C-H stretch,”
Polyaspartate-Ionene/Na+-Montmorillonite Nanocomposites as Novel Adsorbent for Anionic Dye; Effect of Ionene Structure DOI: 10.3390/polym12122843 -
confidence 1.0
“3350 PU: Polyurethane, DNP: Donepezil hydrochloride, PVP: Polyvingl pyrrolidone cm-1 and 2944 bands from N-H and C-H groups.”
Gencturk 等 - 2020 - Effects of Polyvinylpyrrolidone and Ethyl Cellulos DOI: 10.4274/tjps.galenos.2019.87094 -
Alkyl C-H confidence 1.0
“cm(cid:5)1 N-H and 3309.2 for amide A,stretching tion bands at 3324.8 and aqueous extracts tested, ethanol was the most active with a cm(cid:5)1 cm(cid:5)1 and 2832.7 were assigned vibrations bands between 2943.7 μg (cid:1) of 324.55 0.66 m”
Phytochemical screening, polyphenols, flavonoids and tannin content, antioxidant activities and FTIR characterization of Marrubium vulgare L. from 2 different localities of Northeast of Morocco DOI: 10.1016/j.heliyon.2020.e05609 -
Alkyl C-H confidence 1.0
“The bands at 2988, 2876cm-1 C-H tures of the carbonaceous clots suggest that the clots 2944, 2908, and are due to stretching vi-”
FTIR microspectroscopy of carbonaceous matter in ~ 3.5 Ga seafloor hydrothermal deposits in the North Pole area, Western Australia DOI: 10.1186/s40645-018-0242-1
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