What absorbs at 794 cm⁻¹ in an FTIR spectrum?
A band near 794 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 794 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.
Possible functional-group assignments
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| Silicon-oxygen (Si-O) | 6 | 5 | 1.0 |
| Metal oxygen | 2 | 2 | 1.0 |
| Siloxane (Si-O-Si) | 2 | 2 | 1.0 |
| N-O bond | 2 | 1 | 1.0 |
| Hydroxyl (O-H) | 1 | 1 | 1.0 |
| Alkyl C-H | 1 | 1 | 1.0 |
| Silicon (Si) | 1 | 1 | 1.0 |
| Silicon carbon | 1 | 1 | 0.9 |
Ranking reflects accumulated literature evidence, not a single fixed rule. Always confirm against your sample context.
Possible materials
| Material | Supporting peaks | Overlapping groups | Cited sources |
|---|---|---|---|
| silica nanoparticles | 794, 1718, 2925 | Silicon-oxygen (Si-O), Siloxane (Si-O-Si) | 1 |
| nanoparticles | 794, 1732, 1647 | Metal oxygen | 1 |
| clay | 794, 1736, 2855 | Silicon-oxygen (Si-O), Siloxane (Si-O-Si) | 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 794 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.
Literature behind these assignments
-
Silicon-oxygen (Si-O) confidence 1.0
“For SiO 2 cm-1 these are the longitudinal and the transverse surface phonon modes at 1132 and 794 cm-1, respectively.”
Patoka 等 - 2016 - Nanoscale plasmonic phenomena in CVD-grown MoS2 mo DOI: 10.1364/OE.24.001154 -
confidence 1.0
“to the Si-O-Si symmetric stretching absorption peak at 794 The determination of ultramarine could not be ascertained through FTIR analysis.”
Multi-Method Analysis of Painting Materials in Murals of the North Mosque (Linqing, China) DOI: 10.3390/coatings13071298 -
Metal oxygen confidence 1.0
“Comparison of the IR spectra of all 627cm-1 of the three kinds of nanoparticles, absorption peaks at are observed, corresponding to the Fe-O vibration from the original cm-1, cm-1, The absorption bands at 794 953 1075 magnetite phase[25].”
A new method of synthesis well-dispersion and dense Fe3O4@SiO2 magnetic nanoparticles for DNA extraction DOI: 10.1016/j.jmmm.2017.03.025 -
confidence 1.0
“coupled out-of-plan vibration band of Al-O and Si-O cm-1), cm-1), Si-O stretching band of silica (794.13 (624.71 cm-1) deformation band of Al-O-Si (520.49 and deformaLinear cm-1) tion band of Si-O-Si (467.88 (Fig.”
Ghaleh 等 - 2020 - Experimental evaluation of thiamine as a new clay DOI: 10.1007/s12182-020-00466-6 -
Silicon (Si) confidence 1.0
“The next peak at 937 cm-1 peak at 794 cm-1 cm-1 cm-1 at 794 corresponds to Si-O-Si symmetric vibration [23,24].”
Novel Synthesis of Core-Shell Silica Nanoparticles for the Capture of Low Molecular Weight Proteins and Peptides DOI: 10.3390/molecules22101712 -
Alkyl C-H confidence 1.0
“Additionally, the characteristic peaks at 794 cm-1 may belong to the C-H out-ofplane deformational vibration mode of the PPy ring [42,43].”
Effect of Ultrasonication Parameters on the Structural, Morphological, and Electrical Properties of Polypyrrole Nanoparticles and Optimization by Response Surface Methodology DOI: 10.3390/polym15061528 -
Hydroxyl (O-H) confidence 1.0
“The adsorption peaks at 3673, 1574, 1047 and was optimally adsorbed at pH 5.0, GMB600 dosage cm-1 794 were attributed to the stretching vibration of 0.4 g/L and contact time for 150min when initial RhB hydroxyl proups (-OH), the bending vib”
Lu 等 - 2020 - Adsorption of Rhodamine B from Aqueous Solution by DOI: 10.15244/pjoes/112207 -
N-O bond confidence 1.0
“Application to Jungfraujoch (CO stretching) and 794 (NO bending), in regions fro 2”
Mahieu 等 - 2021 - First retrievals of peroxyacetyl nitrate (PAN) fro DOI: 10.1525/elementa.2021.00027
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