What absorbs at 2892 cm⁻¹ in an FTIR spectrum?
A band near 2892 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 2892 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 | 9 | 9 | 1.0 |
| Hydroxyl (O-H) | 2 | 2 | 1.0 |
| Methoxy (OCH3) | 1 | 1 | 1.0 |
| Methacrylate | 1 | 1 | 1.0 |
| C-O single bond | 1 | 1 | 1.0 |
| Acetate | 1 | 1 | 1.0 |
| Carboxyl (COOH) | 1 | 1 | 1.0 |
| Carbohydrate | 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 |
|---|---|---|---|
| PEG | 2892, 1650, 1342 | Alkyl C-H, Hydroxyl (O-H), Methacrylate | 1 |
| MWCNT | 2892, 2876, 1430 | Alkyl C-H, Hydroxyl (O-H), Methoxy (OCH3) | 1 |
| nanocellulose | 2892, 1540, 1646 | Alkyl C-H, Hydroxyl (O-H), Methacrylate | 1 |
| nanocomposites | 2892, 1717, 1630 | Alkyl C-H, Hydroxyl (O-H), Methacrylate | 1 |
| gold nanoparticles | 2892, 1638, 3252 | Alkyl C-H, Methacrylate, Hydroxyl (O-H) | 1 |
| AuNPs | 2892, 1646, 1721 | Hydroxyl (O-H), Alkyl C-H, Methacrylate | 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 2892 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
“3 2 cm-1 Consent for publication respectively..Bands near 3425 (O-H stretching vibraAll authors are willing to submit the article in the journal and they have no cm-1 tion) and peak at 2892 was due to the C-H stretching conflict of interest”
Hanif 和 Zaman - 2017 - Thiolation of arabinoxylan and its application in DOI: 10.1186/s40199-017-0172-2 -
Carbohydrate confidence 1.0
“3343cm-1 2892cm-1 2y¼15(cid:2) untreated samples shows three distinct peaks at (cellulose I) to (cela peak shift at (10(cid:2) 17(cid:2) lulose II)-related gOH.”
Khajavi 等 - 2013 - Alkali treatment of cotton yarns with ultrasonic b DOI: 10.1177/0040517512467077 -
Carboxyl (COOH) confidence 1.0
“A recent report on cm-1 (C-H scissoring and bending), 921 (carboxylic acids, polyethyleneimine capped AuNPs conjugated to epithecm-1 cm-1 aliphatic C-H stretching), 2892 and 2952 lial cell adhesion molecule (EpCAM) monoclonal anti-”
Hetero-Functionalized Gold Nanoparticles to Silence AU-Rich Element Containing mRNAs in RAGE-Expressing Inflammatory Cells: Preparation, Characterization, and <i>In</i>-<i>Vitro</i> Evaluation DOI: 10.1166/jnn.2018.14648 -
Alkyl C-H confidence 1.0
“7b Absorption band Band assignment a 3340 ± 5 O-H stretching b 2892 ± 5 C-H stretching c 1645 ± 5 water bending vibrations d 1376 ± 1 C-H bending e 1002-1029 C-O at C3;”
A turning point in the bacterial nanocellulose production employing low doses of gamma radiation DOI: 10.1038/s41598-022-11010-4 -
Alkyl C-H confidence 1.0
“LLM confirmed rule peak-group candidate”
Pearl-white gallstones: A report of a case and a chemical analysis by FTIR and XRD DOI: 10.1016/j.ijscr.2021.106449 -
Alkyl C-H confidence 1.0
“As can be seen, the intensity cm-1 cm-1 the typical absorption bands of wood (2892 for C-H stretching vibration, 1734 of the typical absorption bands of wood (2892 cm-1 for C-H stretching vibration, 1734 cm-1”
Deposition of Zinc Oxide Coatings on Wood Surfaces Using the Solution Precursor Plasma Spraying Process DOI: 10.3390/coatings11020183 -
Acetate confidence 1.0
“Furthermore, the absorption peaks at 1143, 1103, and 1052 were detected, HP-β-CD FTIR spectra at 3420 cm-1 could be assigned to the O-H stretching, and the peaks at 2892 owing to the C-O-C stretching and vibration in the PEG.”
Kumar 等 - 2022 - Flexible Temperature Sensor Utilizing MWCNT Doped DOI: 10.3390/mi13020197 -
Alkyl C-H confidence 1.0
“LLM confirmed rule peak-group candidate”
Ozkaya 等 - 2008 - 2-pyrrolidone - Capped Mn3O4 nanocrystals DOI: 10.2478/s11532-008-0041-4
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