What absorbs at 2156 cm⁻¹ in an FTIR spectrum?
A band near 2156 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 6 cited sources
Quick answer
A band near 2156 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.
Mulige funktionelle gruppetildelinger
| Funktionel gruppe | Understøttende fakta | Citerede kilder | Højeste tillid |
|---|---|---|---|
| Adsorbed carbon monoxide | 2 | 1 | 1,0 |
| Siloxane (Si-O-Si) | 1 | 1 | 1,0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1,0 |
| Hydroxyl (O-H) | 1 | 1 | 1,0 |
| C#c | 1 | 1 | 0,9 |
Rangering afspejler akkumulerede litteraturbeviser, ikke en enkelt autoritativ regel. Bekræft altid mod din prøvekontekst.
Possible materials
| Materiale | Understøttende toppe | Overlapping groups | Citerede kilder |
|---|---|---|---|
| TiO2 | 2156, 1700, 1093 | Hydroxyl (O-H) | 1 |
| GO | 2156, 1720, 1182 | Hydroxyl (O-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 2156 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.
Litteratur bag disse tildelinger
-
Hydroxyl (O-H) tillid 1,0
“In cm-1, particular, beside the quite intense band at 2156 due to the presence of hydroxyls, an intense peak cm-1, cm-1”
Cesano 等 - 2010 - Designing TiO2 Based Nanostructures by Control of DOI: 10.1021/jp9087207 -
Adsorbed carbon monoxide tillid 1,0
“the predominant associates are the pyrrole-NH/carbon monoxide Hence, the results indicate that in the xenon matrix, once cm-1, and the form C, which gives rise to the band at 2155.9 formed by photolysis of P2C, the CO molecule shows an”
Infrared Spectra and Photochemistry of Matrix-Isolated Pyrrole-2-carbaldehyde DOI: 10.1021/jp911118v -
tillid 1,0
“observed at 2156 A peak of Si-O-Si was also visible at uniformly distributed.”
Khan 等 - 2021 - The Structural, Physical, and In Vitro Biological DOI: 10.14744/eej.2020.36349 -
tillid 1,0
“6 Background substracted DRIFT spectra showing a band at 2156 S14†), CO suggesting the conversion of the ketonic stretch cm-1 CO assigned to stretch vibration on Cu during TPD of 2,5-dmf CO Cu-ZSM-5IJ22).”
Valorisation of 2,5-dimethylfuran over zeolite catalysts studied by on-line FTIR-MS gas phase analysis DOI: 10.1039/d1cy01312b -
tillid 0,9
“Explicit assignment in text.”
Gutierrez 等 - 2012 - Liquid phase hydrogenation of crotonaldehyde over DOI: 10.1016/j.apcata.2012.06.011 -
C#c tillid 0,9
“Explicit: 'at 2156 for SWCNT-1'.”
Mateos-Gil 等 - 2015 - Electroactive carbon nanoforms a comparative stud DOI: 10.1039/c0xx00000x
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