What absorbs at 1804 cm⁻¹ in an FTIR spectrum?
A band near 1804 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 1804 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.
Possibili assegnazioni di gruppi funzionali
| Gruppo funzionale | Fatti di supporto | Fonti citate | Affidabilità massima |
|---|---|---|---|
| Carbonyl (C=O) | 8 | 3 | 1,0 |
| Methacrylate | 4 | 2 | 1,0 |
| Acetate | 4 | 2 | 1,0 |
| Ketone | 3 | 2 | 1,0 |
| Ester | 3 | 2 | 1,0 |
| Carboxyl (COOH) | 3 | 2 | 1,0 |
| Amide | 3 | 2 | 1,0 |
| Methoxy (OCH3) | 2 | 0 | 1,0 |
| C-O single bond | 2 | 0 | 1,0 |
La classifica riflette le prove bibliografiche accumulate, non una singola regola autorevole. Conferma sempre nel contesto del tuo campione.
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 1804 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.
Letteratura dietro queste assegnazioni
-
Carbonyl (C=O) affidabilità 1,0
“LLM confirmed rule peak-group candidate”
Yasin 等 - 2023 - A Unique Modified Eggshell Method as a Model to Re DOI: 10.13005/ojc/390320 -
Acetate affidabilità 1,0
“The spectrum for palmitoyl chloride shows that a sharp peak at 1804 is due to the presence of the C=O stretch band for acid chlorides [40].”
Development of Water Repellent, Non-Friable Tannin-Furanic-Fatty Acids Biofoams DOI: 10.3390/polym14225025 -
Acetate affidabilità 1,0
“The peak at C=O cm-1 1804 can thus be attributed to symmetric stretch which is expected to appear at C=O higher energy than the asymmetric stretch.”
Tarekegne 等 - 2020 - Strong visible-light emission in annealed poly(acr DOI: 10.1364/OME.411329
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