What absorbs at 808 cm⁻¹ in an FTIR spectrum?
A band near 808 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 8 cited sources
Snabbt svar
A band near 808 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.
Möjliga identifieringar av funktionella grupper
| Funktionell grupp | Stödjande fakta | Citerade källor | Högsta förtroende |
|---|---|---|---|
| Silicon-oxygen (Si-O) | 7 | 6 | 1,0 |
| Alkyl C-H | 4 | 4 | 1,0 |
| Silicon (Si) | 3 | 3 | 1,0 |
| Metal oxygen | 3 | 3 | 1,0 |
| Amide | 2 | 2 | 1,0 |
| N h | 2 | 2 | 1,0 |
| Aromatic ring | 2 | 2 | 1,0 |
| Nitrogen heterocycle | 2 | 2 | 1,0 |
| Siloxane (Si-O-Si) | 2 | 2 | 1,0 |
| Methacrylate | 2 | 1 | 1,0 |
| Acetate | 2 | 1 | 1,0 |
| Ring structure | 1 | 1 | 1,0 |
| Ketone | 1 | 1 | 1,0 |
| Ester | 1 | 1 | 1,0 |
| Carboxyl (COOH) | 1 | 1 | 1,0 |
| Carbonyl (C=O) | 1 | 1 | 1,0 |
| Water (H2O) | 1 | 1 | 1,0 |
| Secondary amine | 1 | 1 | 1,0 |
| Methoxy (OCH3) | 1 | 0 | 1,0 |
| C-O single bond | 1 | 0 | 1,0 |
Rankingen speglar ackumulerade litteraturbevis, inte en enda auktoritativ regel. Bekräfta alltid mot din provkontext.
Möjliga material
| Material | Stödjande toppar | Överlappande grupper | Citerade källor |
|---|---|---|---|
| SiO2 | 808, 1739, 699 | Silicon-oxygen (Si-O), Alkyl C-H, Silicon (Si) | 1 |
| polypropylene | 808, 1030, 1600 | Alkyl C-H | 1 |
| magnetite | 808, 1740, 1263 | Metal oxygen, Silicon-oxygen (Si-O) | 1 |
| Polyvinyl Alcohol | 808, 1141, 1640 | Alkyl C-H | 1 |
Material visas endast när samma litteraturpool stöder detta band och minst en ytterligare karakteristisk topp.
Spektrumlogik
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 808 cm⁻¹ is usually not enough for material identification by itself.
Användning i verkligheten
Denna typ av fråga är vanlig inom polymeridentifiering, screening av okänd plast, felsökning av kvalitetskontroll, verifiering av återvunnet material och litteraturstödd toppidentifieringsgranskning.
Vanliga misstag
- Behandla ett isolerat band som bevis på ett material utan att kontrollera minst en eller två stödjande toppar.
- Ignorerar överlapp: flera funktionella grupper kan bidra nära samma vågtal.
- Hoppa över validering när tillsatser, blandningar, oxidation eller föroreningar kan förvränga spektrat.
Verifieringsråd
När oklarhet kvarstår, validera hypotesen med DSC, GC-MS eller TGA, särskilt för blandningar, nedbrutna prover och fyllda polymerer.
Litteratur bakom dessa identifieringar
-
Silicon (Si) förtroende 1,0
“The adsorption cm-1 cm-1 peaks at around 808 and 457 were ascribed to Si-O (symmetric stretching vibration) [41-43].”
Study of Polyvinyl Alcohol-SiO2 Nanoparticles Polymeric Membrane in Wastewater Treatment Containing Zinc Ions DOI: 10.3390/polym13111875 -
förtroende 1,0
“Peak at 460 for Si-O-Si bending and at cm-1 808 for stretching of the Si-O-Si.”
Nanostructure and Property of Electrospun SiO2-Cellulose Acetate Nanofiber Composite by Electrospinning DOI: 10.1016/j.egypro.2016.12.133 -
Alkyl C-H förtroende 1,0
“In the spectra of non-aged PPc and PPcr, the main cm-1, PP bands were observed at 808 cm-1, due to the angular deformation of the out-of-plane PP bands were observed at 808 due to the angular deformation of the out-of-plane cm-1 cm-1,corres”
From Waste to Potential Reuse: Mixtures of Polypropylene/Recycled Copolymer Polypropylene from Industrial Containers: Seeking Sustainable Materials DOI: 10.3390/su14116509 -
förtroende 1,0
“amino bands (NH bending, 808 and 780”
Bellido-Aguilar 等 - 2019 - Effect of a fluoroalkyl-functional curing agent on DOI: 10.1016/j.surfcoat.2019.02.006 -
Water (H2O) förtroende 1,0
“H-O-H bending modes of 1590 - 1650 vibration Wagging modes of 808 3 Results and discussion vibration of coordinated water v1 symmetric stretching 930 - 995 3.1 Effect of sludge type PO43vibration of units v2 symmetric bending 404 - 470 Init”
Damalerio 等 - 2019 - Phosphorus recovery from wastewater and sludge DOI: 10.1051/matecconf/201926806016 -
Silicon (Si) förtroende 1,0
“3 4000 4 cm-1 The band at 808 could be attributed to the Si-O-Si”
Synthesis of core–shell structured FAU/SBA-15 composite molecular sieves and their performance in catalytic cracking of polystyrene DOI: 10.1080/14686996.2017.1396561 -
förtroende 1,0
“Si-O and Be-O bond vibration is observed at wavenumber 808 cm-1.”
Fawzy - 2021 - Separation of fine beryl from quartz via magnetic DOI: 10.37190/ppmp/132329 -
Nitrogen heterocycle förtroende 1,0
“The peak at 808 cm-1 is assigned to the breathing mode of the triazine units (Figcm-1 vibrations.”
Underlying Mechanisms of Reductive Amination on Pd-Catalysts: The Unique Role of Hydroxyl Group in Generating Sterically Hindered Amine DOI: 10.3390/ijms23147621
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