What absorbs at 1018 cm⁻¹ in an FTIR spectrum?
A band near 1018 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 1018 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 | 19 | 17 | 1.0 |
| Methoxy (OCH3) | 16 | 14 | 1.0 |
| Methacrylate | 16 | 14 | 1.0 |
| Acetate | 16 | 14 | 1.0 |
| Silicon-oxygen (Si-O) | 8 | 8 | 1.0 |
| Alkyl C-H | 7 | 7 | 1.0 |
| Carbohydrate | 5 | 5 | 1.0 |
| Silicon (Si) | 4 | 4 | 1.0 |
| Siloxane (Si-O-Si) | 4 | 4 | 1.0 |
| Ester | 2 | 2 | 1.0 |
| N-O bond | 2 | 2 | 1.0 |
| Aromatic ring | 2 | 2 | 1.0 |
| Hydroxyl (O-H) | 2 | 2 | 1.0 |
| Phosphate (PO4) | 1 | 1 | 1.0 |
| Carboxyl (COOH) | 1 | 1 | 1.0 |
| Secondary amine | 1 | 1 | 1.0 |
| C n single bond | 1 | 1 | 1.0 |
| Amide | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| C-S single bond | 1 | 1 | 1.0 |
| Oxygen heterocycle | 1 | 1 | 1.0 |
| Metal oxygen | 1 | 1 | 1.0 |
| Chlorine | 1 | 0 | 1.0 |
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 |
|---|---|---|---|
| polyurethane | 1018, 2270, 1700 | Methacrylate, Acetate, C-O single bond | 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 1018 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
-
C-O single bond confidence 1.0
“LLM confirmed rule peak-group candidate”
Daud 等 - 2013 - Preparation and Characterization of Plasticized Pa DOI: 10.1063/1.4858749 -
Alkyl C-H confidence 1.0
“1155 C (cid:31)O stretching vibration (S-type lignin) 1018 Aryl C-H plane deformation (G- >S-) MC 0.5 MC 3”
Hao 等 - 2018 - The Influence of a Thermal Treatment on the Decay DOI: 10.1155/2018/8461407 -
Ester confidence 1.0
“The ethylene glycol CH wagging mode 2 cm-1 O-CH at 1370 and 1340 and the ester stretch at 2 cm-1 1018 are all absent, suggesting that the hydrolysis”
Ma 等 - 2004 - Crystal structure and composition of poly(ethylene DOI: 10.1021/ma0486905 -
Metal oxygen confidence 1.0
“respectively assigned as and The peak at 1018 was characteristic of the stretching = vibration of the terminal vanadyl, V O [19].”
Vanadium pentoxide nanobelts: One pot synthesis and its lithium storage behavior DOI: 10.1002/crat.201200122 -
C-O single bond confidence 1.0
“found at 1745 and 1606 C-O-C stretching was found at peak 1018 Spectrum of SiO 2-cellulose acetate nanofiber showed that intensity of vibration band peak of OH group at peak 3444 was increased.”
Nanostructure and Property of Electrospun SiO2-Cellulose Acetate Nanofiber Composite by Electrospinning DOI: 10.1016/j.egypro.2016.12.133 -
Acetate confidence 1.0
“Stretch C-O 1018 Stretch C-O (CH-O) 1660-1600”
Identification of cellulose nitrate based adhesive repairs in archaeological pottery of the University of Melbourne’s Middle Eastern archaeological pottery collection using portable FTIR-ATR spectroscopy and PCA DOI: 10.1186/s40494-016-0116-z -
Acetate confidence 1.0
“0.4 while the peak located at 1018 cm - is attributed to C-O I ..”
Abidi 和 Hequet - 2005 - Fourier transform infrared analysis of trehalulose DOI: 10.1177/0040517505057527 -
Acetate confidence 1.0
“Ethanol and fermented ethanol extracts (Figure 2a) show distinctive bands at 1072 and 1018 cm-1 that can be associated with C-O deformation of secondary alcohols and C-H ring and side group vibrations.”
HPTLC and FTIR Fingerprinting of Olive Leaves Extracts and ATR-FTIR Characterisation of Major Flavonoids and Polyphenolics DOI: 10.3390/molecules26226892
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