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
Possible functional-group assignments
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| 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 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Literature behind these assignments
-
Carbonyl (C=O) confidence 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 confidence 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 confidence 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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