What absorbs at 404 cm⁻¹ in an FTIR spectrum?
A band near 404 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 4 cited sources
Quick answer
A band near 404 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.
Возможные назначения функциональных групп
| Функциональная группа | Подтверждающие факты | Цитируемые источники | Максимальная достоверность |
|---|---|---|---|
| Methoxy (OCH3) | 1 | 1 | 1,0 |
| Methacrylate | 1 | 1 | 1,0 |
| C-O single bond | 1 | 1 | 1,0 |
| Acetate | 1 | 1 | 1,0 |
| Amide | 1 | 1 | 1,0 |
| Protein | 1 | 1 | 1,0 |
| N-O bond | 1 | 1 | 1,0 |
Ранжирование отражает накопленные литературные данные, а не единственное авторитетное правило. Всегда проверяйте в контексте вашего образца.
Possible materials
| Материал | Поддерживающие пики | Overlapping groups | Цитируемые источники |
|---|---|---|---|
| Polyaniline | 404, 1565, 1570 | Methacrylate, Acetate | 1 |
Materials are shown only when the same literature pool supports this band and at least one additional characteristic peak.
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 404 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.
Литература, лежащая в основе этих назначений
-
достоверность 1,0
“2 38 285.0 eV that has been attributed to Ru 3d as well as the absence of a diazonium peak at 403.8 39 40 eV.28,56 Titanium peaks in the XPS spectra were standard for TiO 2, with no peak present that would”
Surface Grafting of Ru(II) Diazonium-Based Sensitizers on Metal Oxides Enhances Alkaline Stability for Solar Energy Conversion DOI: 10.1021/acsami.7b16641 -
достоверность 1,0
“The appearance of a t broad peak at 403.71 eV is due to the N 1s shake up satellite of the ionized nitrogen atoms [40].”
Investigation of the binding of dioxin selective pentapeptides to a polyaniline matrix DOI: 10.1016/j.synthmet.2012.04.012. -
Protein достоверность 1,0
“The other major bands ν 404 corresponded to the principal cellular components such as the proteins (the amide I band cm-1;”
Cointet 等 - 2019 - Lipids in benthic diatoms A new suitable screenin DOI: 10.1016/j.algal.2019.101425 -
Acetate достоверность 1,0
“C-O-C stretching 404 bands (both the glucopyranose ring and glycosidic bridges) are observed in the cm-1.”
Lefroy 等 - 2021 - A natural, cellulose-based microgel for water-in-o DOI: 10.1016/j.foodhyd.2020.106408
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