What absorbs at 408 cm⁻¹ in an FTIR spectrum?
A band near 408 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
Stutt svar
A band near 408 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.
Mögulegar úthlutun virkra hópa
| Virkur hópur | Stuðningsstaðreyndir | Tilvitnuð heimildir | Mesta öryggi |
|---|---|---|---|
| Methoxy (OCH3) | 2 | 2 | 1,0 |
| Methacrylate | 2 | 2 | 1,0 |
| C-O single bond | 2 | 2 | 1,0 |
| Acetate | 2 | 2 | 1,0 |
| Metal oxygen | 1 | 1 | 1,0 |
| Methyl | 1 | 1 | 1,0 |
| Alkyl C-H | 1 | 1 | 1,0 |
| Ester | 1 | 1 | 1,0 |
| Silicon (Si) | 1 | 1 | 1,0 |
| Siloxane (Si-O-Si) | 1 | 1 | 1,0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1,0 |
Röðun endurspeglar uppsöfnuð ritrýnisgögn, ekki eina valdboðsreglu. Staðfestu alltaf í samhengi við sýnið þitt.
Möguleg efni
| Efni | Stuðningstindar | Skarast hópar | Tilvitnuð heimildir |
|---|---|---|---|
| PLA | 408, 1650, 1073 | Methacrylate, Acetate, Methoxy (OCH3) | 1 |
| PE | 408, 1414, 1700 | Methacrylate, Acetate, Methoxy (OCH3) | 1 |
| PP | 408, 1700, 1043 | Methacrylate, Acetate, Methoxy (OCH3) | 1 |
Efni birtast aðeins þegar sama bókmenntasafn styður þessa band og að minnsta kosti einn viðbótar einkennandi hámark.
Rófrök
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 408 cm⁻¹ is usually not enough for material identification by itself.
Raunveruleg notkun
Þessi tegund fyrirspurna er algeng við auðkenningu fjölliða, skimun óþekktra plasttegunda, bilanaleit í gæðaeftirliti, staðfestingu endurunnins efnis og bókmenntabakkaða endurskoðun á hápunktum.
Algeng mistök
- Meðhöndla eina einangraða öldulengd sem sönnun á efni án þess að athuga að minnsta kosti einn eða tvo stuðningstoppa.
- Hunsa skörun: mörg virkir hópar geta lagt sitt af mörkum nálægt sömu bylgjutölunni.
- Að sleppa staðfestingu þegar aukefni, blöndur, oxun eða mengun geta brenglað litrófið.
Staðfestingarráðgjöf
Þegar tvíræðni er eftir, staðfestu tilgátuna með DSC, GC-MS eða TGA, sérstaklega fyrir blöndur, niðurbrotin sýni og fylltar fjölliður.
Ritlist á bak við þessar úthlutanir
-
Silicon-oxygen (Si-O) öryggi 1,0
“α-Fe 295 2O 3 330 O-Si-O deformation vibration 408 Si-O-Si bending vibration”
Wu 等 - 2022 - Comparison of Natural and Dyed Fire Opal DOI: 10.3390/cryst12030322 -
Acetate öryggi 1,0
“vibration showed a band at 408 In contrast to IR spectra, C-O bond ester vibrations in PLA were weak, cm-1 and the Raman bands with maxima at 1043 and 1128 were associated with C-CH vibrations.”
Optical photothermal infrared spectroscopy with simultaneously acquired Raman spectroscopy for two-dimensional microplastic identification DOI: 10.1038/s41598-022-23318-2 -
Acetate öryggi 1,0
“408 cm-1, and C-O-C + C-CH3 vibration assigned to 302-315 cm-1.”
Impact of the Fused Deposition (FDM) Printing Process on Polylactic Acid (PLA) Chemistry and Structure DOI: 10.3390/app7060579 -
Metal oxygen öryggi 1,0
“-1 The spectra of vine black show additional bands at 224, 243 and 290 cm due to -1 symmetric bending of the Fe-O bond, bands at 408, 495, 608 and 659 cm due to symmetric and asymmetric vibrational modes of Fe-O bond [61] and bands at”
Lluveras-Tenorio 等 - 2019 - A multi-analytical characterization of artists' ca DOI: 10.1007/s10973-019-08522-z
Ertu með róf með þessu bandi?
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