What absorbs at 1198 cm⁻¹ in an FTIR spectrum?
A band near 1198 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 1198 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 |
|---|---|---|---|
| C-O single bond | 3 | 3 | 1.0 |
| Methoxy (OCH3) | 2 | 2 | 1.0 |
| Methacrylate | 2 | 2 | 1.0 |
| Acetate | 2 | 2 | 1.0 |
| Siloxane (Si-O-Si) | 1 | 1 | 1.0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1.0 |
| Silicon (Si) | 1 | 1 | 1.0 |
| Amide | 1 | 1 | 1.0 |
| C c single bond | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Methyl | 1 | 1 | 1.0 |
| Alkyl C-H | 1 | 1 | 1.0 |
| Carbohydrate | 1 | 1 | 1.0 |
| Carbonate | 1 | 0 | 0.5 |
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 |
|---|---|---|---|
| nanotubes | 1198, 1735, 1630 | Methacrylate, Acetate, Methoxy (OCH3) | 1 |
| collagen | 1198, 1408, 1660 | Methacrylate, Acetate, Methoxy (OCH3) | 1 |
| dentin | 1198, 575, 1740 | Methacrylate, Acetate | 1 |
| nanocomposites | 1198, 1717, 1630 | C-O single bond, Methacrylate, Acetate | 1 |
| magnetite | 1198, 1740, 1263 | Methacrylate, Acetate, Methoxy (OCH3) | 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 1198 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
-
Carbohydrate confidence 1.0
“In Cannonau samples the visible region at nm of both wines, the spectral region around 1047 attributed to sugar in cm(cid:0) 1 spectra correlated with FT-IR peaks at 1198 and 1016 glycosylated phenols, is inversely correlated with time (red”
Characterization of the medium infrared spectra of polyphenols of red and white wines by integrating FT IR and UV–Vis spectral data DOI: 10.1016/j.lwt.2021.111604 -
Alkyl C-H confidence 1.0
“SA shows many bands in this spectral region because of the presence of the cm-1, C-H bending modes of the methyl groups, showing the most intense band at 1198”
Vibrational Study (Raman, SERS, and IR) of Plant Gallnut Polyphenols Related to the Fabrication of Iron Gall Inks DOI: 10.3390/molecules27010279 -
C c single bond confidence 1.0
“peak at 704-719 is the C-S-C ring cm-1 deformation for thiophene rings while that at around 1198 is the C-C symmetric stretching and”
Bulk Heterojunction Solar Cell with Nitrogen-Doped Carbon Nanotubes in the Active Layer: Effect of Nanocomposite Synthesis Technique on Photovoltaic Properties DOI: 10.3390/ma8052415 -
Acetate confidence 1.0
“cm-1 of the TA compound are 3450 (O-H stretching, strong), Figure 3 shows the optimized structures of two different cm-1 cm-1 1740 (C=O stretching, strong), 1630 (aromatic C=C possibilities for the supramolecular interaction of complex cm-1”
Santos 等 - 2016 - Hybrid Self-Assembled Materials Constituted by Fer DOI: 10.5935/0103-5053.20150322 -
Amide confidence 1.0
“Materials2021,14,3501 6of12 cm-1 cm-1, cm-1 1364 (amide III and CH wag vibration), 1198 and 1257 (CH twist-wag 2”
Characterization and Combustion Behavior of Single-Use Masks Used during COVID-19 Pandemic DOI: 10.3390/ma14133501 -
Acetate confidence 1.0
“a phenol and ether C-C, C-O stretching at 1198 and 1038 These observations are in agreement with previous studies on the interactions of PACs with collagen and gelatin [16,32].”
Collagen-collagen interactions mediated by plant-derived proanthocyanidins: a spectroscopic and atomic force microscopy study DOI: 10.1016/j.actbio.2016.05.026. -
Silicon (Si) confidence 1.0
“Further supporting evidence was cm-1 obtained from FTIR and TG, for example, the vibration at 1198 corresponds to oC Si-O-Si stretching mode and the mass loss at ca.”
Zhu 等 - 2008 - In situ synthesis of surfactantsilane-modified hy DOI: 10.1016/j.jcis.2007.11.037 -
C-O single bond confidence 0.8
“Range 1218-1198 assigned to ν(C-O).”
Graur 等 - 2023 - Novel Antioxidants Based on Selected 3d Metal Coor DOI: 10.17344/acsi.2022.7885
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