What absorbs at 1150 cm⁻¹ in an FTIR spectrum?
A band near 1150 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 1150 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 | 61 | 59 | 1.0 |
| Acetate | 57 | 56 | 1.0 |
| Methacrylate | 56 | 55 | 1.0 |
| Methoxy (OCH3) | 54 | 53 | 1.0 |
| Hydroxyl (O-H) | 17 | 16 | 1.0 |
| Alkyl C-H | 13 | 12 | 1.0 |
| Carbohydrate | 12 | 12 | 1.0 |
| Ester | 9 | 9 | 1.0 |
| Amide | 7 | 7 | 1.0 |
| C c single bond | 7 | 6 | 1.0 |
| Carboxyl (COOH) | 6 | 6 | 1.0 |
| S eq o | 4 | 4 | 1.0 |
| Carbonyl (C=O) | 4 | 4 | 1.0 |
| Aromatic ring | 4 | 4 | 1.0 |
| Siloxane (Si-O-Si) | 4 | 3 | 1.0 |
| Ring structure | 3 | 3 | 1.0 |
| Secondary amine | 3 | 3 | 1.0 |
| C n single bond | 3 | 3 | 1.0 |
| Silicon-oxygen (Si-O) | 3 | 3 | 1.0 |
| Ketone | 3 | 3 | 1.0 |
| Alkene (C=C) | 3 | 3 | 1.0 |
| Nucleic acid | 3 | 3 | 1.0 |
| Aldehyde (CHO) | 3 | 3 | 0.9 |
| Lignin | 2 | 2 | 1.0 |
| N h | 2 | 2 | 1.0 |
| Sulfate (SO4) | 2 | 2 | 1.0 |
| Silicon (Si) | 2 | 2 | 1.0 |
| Phosphate (PO4) | 2 | 2 | 1.0 |
| Fluorine (C-F) | 2 | 1 | 1.0 |
| Hydrogen bond | 1 | 1 | 1.0 |
| Oxygen heterocycle | 1 | 1 | 1.0 |
| Borate | 1 | 1 | 1.0 |
| Lipid | 1 | 1 | 1.0 |
| Protein | 1 | 1 | 1.0 |
| Amine primary | 1 | 1 | 1.0 |
| Sulfonyl | 1 | 1 | 1.0 |
| Chitosan | 1 | 1 | 1.0 |
| N-O bond | 1 | 1 | 1.0 |
| Silicate | 1 | 1 | 1.0 |
| Water (H2O) | 1 | 1 | 1.0 |
| Silicon nitrogen | 1 | 1 | 0.6 |
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 | 1150, 1100, 1080 | Methacrylate, Acetate | 1 |
| STARCH | 1150, 1650, 1540 | Methacrylate, Acetate, C-O single bond | 1 |
| silica nanoparticles | 1150, 1718, 2925 | Methacrylate | 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 1150 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
-
Acetate confidence 1.0
“The 9 cm-1 band observed at 1150 could be attributed to C-O, CH stretching, bending vibrations 2”
Prediction of peroxide value in omega-3 rich microalgae oil by ATR-FTIR spectroscopy combined with chemometrics DOI: 10.1016/j.foodchem.2017.01.013 -
Acetate confidence 1.0
“The major peaks at 1150 cm(cid:0) 1 C-O-H C-O-C peak position is slightly shifted due to the difference in the ionic radii of 2930 correspond to group, group, the”
Synthesis, structural and antibacterial activity of pure, Fe doped, and glucose capped ZnO nanoparticles DOI: 10.1016/j.surfin.2021.101327 -
Silicon (Si) confidence 1.0
“In the fingerprint region, the wavenumbers 1020 and 1150 represent the asymmetric cm-1 cm-1 fingerprint region, the wavenumbers 1020 cm-1 and 1150 cm-1 represent the asymmetric stretching vibrations Si-O-Si.”
Biosynthesized Silica Nanosuspension as Thermal Fluid in Parabolic Solar Panels DOI: 10.3390/e23020142 -
confidence 1.0
“are characteristics of anhydrides, such as the one at On the other hand, when compared to the commercm-1 1150 that is related to the stretching bond cial AL, color and turbidity removal was higher using of -CO group.”
Felipe Tirado 等 - 2017 - EVALUATION OF THE COAGULANT CAPACITY OF STARCH OBT DOI: 10.20937/RICA.2017.33.esp01.11 -
Acetate confidence 1.0
“2 (1-4)-glucosidic cm-1, the the special broad peak of band in poly saccharide unit at 1150 C-O-C cm-1, the (stretching vibration) in OH group stretching vibration peak at 1082 1060-1015 cm-1, cm-1 and peak at is due to CH-OH in the glucose”
Removal of Hexavalent Chromium by Cross-Linking Chitosan and N,N’-Methylene Bis-Acrylamide DOI: 10.1007/s40710-020-00447-2 -
Acetate confidence 1.0
“The peak at 1150 is due to C=O.”
Keyoumu 等 - 2020 - The detailed biological investigations about combi DOI: 10.1016/j.jphotobiol.2019.111666 -
confidence 1.0
“symmetric (1150 stretching vibrational modes.43-45 The former band contains contributions from S-O”
Model-Based Analyses of Confined Polymer Electrolyte Nanothin Films Experimentally Probed by Polarized ATR–FTIR Spectroscopy DOI: 10.1021/acs.jpcc.8b02473 -
Acetate confidence 1.0
“The bands cm-1 at 1150 and 1032 belong to the vibrations of the C-O and C-O-C groups (Fig.”
Identification of sugars and phenolic compounds in honey powders with the use of GC–MS, FTIR spectroscopy, and X-ray diffraction DOI: 10.1038/s41598-020-73306-7
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