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
Brzi odgovor
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.
Moguće dodjele funkcionalnih skupina
| Funkcionalna skupina | Potporni dokazi | Citirani izvori | Najveća pouzdanost |
|---|---|---|---|
| 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 |
Rangiranje odražava akumulirane literaturne dokaze, a ne jedno autoritativno pravilo. Uvijek provjerite u kontekstu vašeg uzorka.
Mogući materijali
| Materijal | Potporni vrhovi | Preklapajuće skupine | Citirani izvori |
|---|---|---|---|
| Polyaniline | 404, 1565, 1570 | Methacrylate, Acetate | 1 |
Materijali su prikazani samo kada ista literatura podržava ovu traku i barem jedan dodatni karakteristični vrh.
Logika spektra
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.
Upotreba u stvarnom svijetu
Ova vrsta upita uobičajena je u identifikaciji polimera, probiru nepoznate plastike, rješavanju problema u kontroli kvalitete, provjeri recikliranog materijala i pregledu dodjele vrhova potkrijepljenom literaturom.
Uobičajene pogreške
- Tretiranje jedne izolirane vrpce kao dokaza materijala bez provjere barem jednog ili dva podržavajuća pika.
- Zanemarivanje preklapanja: više funkcionalnih skupina može doprinositi u blizini istog valnog broja.
- Preskakanje validacije kada aditivi, mješavine, oksidacija ili kontaminacija mogu izobličiti spektar.
Savjet za provjeru
Kada nejasnoća ostane, validirajte hipotezu pomoću DSC, GC-MS ili TGA, posebno za mješavine, degradirane uzorke i punjene polimere.
Literatura iza ovih dodjela
-
pouzdanost 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 -
pouzdanost 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 pouzdanost 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 pouzdanost 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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