What absorbs at 2240 cm⁻¹ in an FTIR spectrum?
A band near 2240 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 2240 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.
Penetapan kumpulan berfungsi yang mungkin
| Kumpulan berfungsi | Fakta sokongan | Sumber dipetik | Keyakinan tertinggi |
|---|---|---|---|
| Nitrile | 5 | 4 | 1.0 |
| Alkyl C-H | 4 | 3 | 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 |
| Secondary amine | 1 | 1 | 1.0 |
| C n single bond | 1 | 1 | 1.0 |
| Amide | 1 | 1 | 1.0 |
| Isocyanate | 1 | 1 | 1.0 |
| C=n | 1 | 0 | 1.0 |
Pemeringkatan mencerminkan bukti literatur terkumpul, bukan satu peraturan berwibawa. Sentiasa sahkan terhadap konteks sampel anda.
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 2240 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.
Literatur di sebalik penetapan ini
-
Isocyanate keyakinan 1.0
“LLM confirmed rule peak-group candidate”
El-Shekeil 等 - 2012 - Effect of pMDI isocyanate additive on mechanical a DOI: 10.1177/0021998310385030) -
Alkyl C-H keyakinan 1.0
“It can be seen that, by increasing intensity of treatment (either the temperature or the duration), It can be seen that, by increasing intensity of treatment (either the temperature or the duration), thepeaksat2940and2240cm-1 the peaks at 2”
Konstantopoulos 等 - 2020 - Introduction of a Methodology to Enhance the Stabi DOI: 10.3390/ma13122749 -
Nitrile keyakinan 1.0
“LLM confirmed rule peak-group candidate”
Novel Mixed Matrix Membranes Based on Polymer of Intrinsic Microporosity PIM-1 Modified with Metal-Organic Frameworks for Removal of Heavy Metal Ions and Food Dyes by Nanofiltration DOI: 10.3390/membranes12010014 -
Nitrile keyakinan 1.0
“LLM confirmed rule peak-group candidate”
Lee 等 - 2021 - Effects of Various Transition Metals on the Therma DOI: 10.21203/rs.3.rs-230180/v1 -
Alkyl C-H keyakinan 1.0
“450° strong C-H peak at vibrations of C-O and C-H in the regions of 2025 to C in all samples could be attributed 2240cm-1 3035cm-1, to evolution of CH and 2620 to respectively;”
Masite 等 - 2022 - Trace Metals, Crude Protein, and TGA-FTIR Analysis DOI: 10.1155/2022/1509569 -
Nitrile keyakinan 1.0
“cm(cid:3)1 about 2240 all samples show the behavior that we already have described before in detail for homopolymer cm(cid:3)1 PAN.21 The starting peak at 2240 disappears with increasing temperature in favor of a new nitrile peak at cm(cid:”
Investigation of the chemical changes during the thermal treatment of acrylonitrile‐co‐methyl acrylate‐polymer (polyacrylonitrile‐precursor) focusing on the fate of the methyl acrylate moiety DOI: 10.1002/app.52074 -
Alkyl C-H keyakinan 1.0
“plasticfibrelyingonit(a).(Toprightandbottompanels)2DFTIR assigned to PU are the following: at 3062 (aromatic CH imaging maps, where the intensity of the following bands was (C-H (C-N stretching region, 2962 stretching), 1743 (C=O mapped: 29”
Assessment of microplastic pollution: occurrence and characterisation in Vesijärvi lake and Pikku Vesijärvi pond, Finland DOI: 10.1007/s10661-019-7843-z -
Acetate keyakinan 1.0
“In addition, the bands at 2240cm-1 are characteristic peaks of CO, which is mainly formed by the 2060 breaking of C-O-C and C=O [20].”
Wang Qing 等 - 2015 - GASEOUS EMISSION AND THERMAL ANALYSIS DURING CO-CO DOI: 10.3176/oil.2015.4.05
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