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
Snel antwoord
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.
Mogelijke functionele-groeptoewijzingen
| Functionele groep | Ondersteunende feiten | Geciteerde bronnen | Hoogste vertrouwen |
|---|---|---|---|
| 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 |
Ranglijst weerspiegelt cumulatief literatuurbewijs, niet één gezaghebbende regel. Bevestig altijd aan de hand van uw monsterecontext.
Spectrumlogica
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.
Gebruik in de praktijk
Dit type query komt vaak voor bij polymeeridentificatie, screening van onbekende kunststoffen, probleemoplossing bij QC, verificatie van gerecycled materiaal en literatuurondersteunde beoordeling van piektoewijzing.
Veelgemaakte fouten
- Het behandelen van een enkele geïsoleerde band als bewijs van een materiaal zonder ten minste een of twee ondersteunende pieken te controleren.
- Overlap negeren: meerdere functionele groepen kunnen bijdragen rond hetzelfde golfgetal.
- Validatie overslaan wanneer additieven, mengsels, oxidatie of verontreiniging het spectrum kunnen verstoren.
Advies voor verificatie
Wanneer dubbelzinnigheid blijft bestaan, valideer de hypothese met DSC, GC-MS of TGA, vooral voor mengsels, gedegradeerde monsters en gevulde polymeren.
Literatuur achter deze toewijzingen
-
Isocyanate vertrouwen 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 vertrouwen 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 vertrouwen 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 vertrouwen 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 vertrouwen 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 vertrouwen 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 vertrouwen 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 vertrouwen 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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