What absorbs at 812 cm⁻¹ in an FTIR spectrum?
A band near 812 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
Quick answer
A band near 812 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.
Mögliche Funktionsgruppenzuweisungen
| Funktionelle Gruppe | Unterstützende Fakten | Zitierte Quellen | Höchstes Vertrauen |
|---|---|---|---|
| Alkyl C-H | 5 | 4 | 1,0 |
| Aromatic ring | 2 | 2 | 1,0 |
| Silicon-oxygen (Si-O) | 2 | 2 | 1,0 |
| Alkene (C=C) | 2 | 2 | 1,0 |
| Metal oxygen | 2 | 1 | 1,0 |
| Silicon (Si) | 1 | 1 | 1,0 |
| Methyl | 1 | 1 | 1,0 |
| Carbon bromine | 1 | 1 | 1,0 |
| C-O single bond | 1 | 1 | 1,0 |
| Phosphate (PO4) | 1 | 1 | 1,0 |
| Ring structure | 1 | 1 | 1,0 |
| N h | 1 | 1 | 1,0 |
| N-O bond | 1 | 1 | 1,0 |
| Carbonyl (C=O) | 1 | 1 | 0,8 |
Das Ranking spiegelt die gesammelte Literatur Evidenz wider, nicht eine einzelne maßgebliche Regel. Bestätigen Sie immer anhand Ihres Probenkontexts.
Possible materials
| Material | Unterstützende Peaks | Overlapping groups | Zitierte Quellen |
|---|---|---|---|
| SiO2 | 812, 1739, 699 | Silicon-oxygen (Si-O), Alkyl C-H | 2 |
| polysaccharide | 812, 1637, 1320 | Alkyl C-H | 1 |
| zeolite | 812, 1013, 1245 | Alkyl C-H, Silicon-oxygen (Si-O) | 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 812 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.
Literatur hinter diesen Zuweisungen
-
N-O bond Vertrauen 1,0
“Again, no peak at 812 ing the absence of residual acrylic acid starting reactant in the synthesized product.”
Synthesis of UV-curable difunctional silane monomer based on 3-methacryloxy propyl trimethoxysilane (3-MPTS) and its UV-curing characteristics and thermal stability DOI: 10.1002/app.31266 -
Vertrauen 1,0
“cm(cid:3)1 integrated peak area of Si-O bands located at 812 increases with increasing amount of silica in the mixture of oxides.”
Jonynaite 等 - 2010 - Spectroscopic analysis of blue cobalt smalt pigmen DOI: 10.1016/j.vibspec.2009.12.005 -
Vertrauen 1,0
“cm-1 bands are seen between 900 and 690 N-H out of the plane bending is visible at 812 cm-1.”
Synthesis of Aloevera/Acrylonitrile based Nanoparticles for targeted drug delivery of 5-Aminosalicylic acid DOI: 10.1016/j.ijbiomac.2017.08.085 -
Vertrauen 1,0
“(O corresponds to oxygen from the corner of the heteropolyanion structure), W-O e-W c IR spectrum of PDPA doped with the PTA heteropolyanions is characterized by the IR (O corresponds to oxygen from the side of the heteropolyanion structure”
The Photoluminescence and Vibrational Properties of Black Phosphorous Sheets Chemically/Electrochemically Functionalized in the Presence of Diphenylamine DOI: 10.3390/polym14214479 -
C-O single bond Vertrauen 1,0
“Bands at 812 cm-1 and 893 cm-1 may be Separations2023,10,103 8of18 related to the presence of αand β-glycosidic bonds [49].”
Extraction, Characterization, and Antioxidant Activity of Polysaccharides from Ajwa Seed and Flesh DOI: 10.3390/separations10020103 -
Alkyl C-H Vertrauen 1,0
“8 , it is observed that the peak at the wave number -1 -1 522.96 cm shows the presence of the C-Br whereas the peak at 812 cm shows the presence -1 -1 of C-H (Alkene).”
Dataset on tribological, characterization and thermal properties of Silicon carbide reinforced polyamide composites for industrial applications DOI: 10.1016/j.dib.2020.105662 -
Alkene (C=C) Vertrauen 1,0
“cm-1, C=C to the deformation of methyl groups at 1379 Moreover, the stretching at 1610 and 812 cm-1,”
Thermocatalytic Pyrolysis of Exhausted Arthrospira platensis Biomass after Protein or Lipid Recovery DOI: 10.3390/en13205246 -
Silicon (Si) Vertrauen 1,0
“Furthermore, the peaks of 812.03 cm-1 assigned for symmetric Si-O (Figure 4) shifted to a shorter wavelength (806.25 cm-1), while bending modes at 470.63 cm-1 did not change after”
Adsorption of Polyelectrolyte onto Nanosilica Synthesized from Rice Husk: Characteristics, Mechanisms, and Application for Antibiotic Removal DOI: 10.3390/polym10020220
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