What absorbs at 1782 cm⁻¹ in an FTIR spectrum?
A band near 1782 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 3 cited sources
Quick answer
A band near 1782 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.
Attributions possibles de groupes fonctionnels
| Groupe fonctionnel | Faits à l＇appui | Sources citées | Confiance maximale |
|---|---|---|---|
| Methacrylate | 2 | 1 | 1,0 |
| Acetate | 2 | 1 | 1,0 |
| Fatty acid | 1 | 1 | 1,0 |
| Imide | 1 | 1 | 1,0 |
| Ketone | 1 | 1 | 1,0 |
| Ester | 1 | 1 | 1,0 |
| Carboxyl (COOH) | 1 | 1 | 1,0 |
| Carbonyl (C=O) | 1 | 1 | 1,0 |
| Amide | 1 | 1 | 1,0 |
| Methoxy (OCH3) | 1 | 0 | 1,0 |
| C-O single bond | 1 | 0 | 1,0 |
Le classement reflète les preuves bibliographiques accumulées, et non une règle faisant autorité. Confirmez toujours dans le contexte de votre échantillon.
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 1782 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.
Bibliographie derrière ces attributions
-
Acetate confiance 1,0
“- 1627.7108 C=O stretch Ketones 1782.1130 1833.5806 -”
Hydrolysis, Microstructural Profiling and Utilization of Cyamopsis tetragonoloba in Yoghurt DOI: 10.3390/fermentation9010045 -
Imide confiance 1,0
“Typical imide bands for P84 are located cm-1 cm-1 cm-1 at 1782 for symmetric CO stretching, at 1716 for asymmetric CO stretching, and at 1359 for”
Effect of ionic liquid on formation of copolyimide ultrafiltration membranes with improved rejection of La3+ DOI: 10.1038/s41598-022-12377-0 -
Fatty acid confiance 1,0
“Wavenumbers responsible for the segregation of cells treated with flusilazole from those treated with carbendazim were also associated with lipid/fatty acid regions (1782, 1705, 1474 cm-1), with some protein contribution (Amide III) and aga”
Strong 等 - 2016 - Infrared spectroscopy detects changes in an amphib DOI: 10.1016/j.aquatox.2016.07.005
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