What absorbs at 1162 cm⁻¹ in an FTIR spectrum?
A band near 1162 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 1162 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 | 17 | 17 | 1.0 |
| Methoxy (OCH3) | 16 | 16 | 1.0 |
| Methacrylate | 16 | 16 | 1.0 |
| Acetate | 16 | 16 | 1.0 |
| Alkyl C-H | 11 | 11 | 1.0 |
| Ester | 4 | 4 | 1.0 |
| Secondary amine | 3 | 3 | 1.0 |
| C n single bond | 3 | 3 | 1.0 |
| Amide | 3 | 3 | 1.0 |
| Hydroxyl (O-H) | 3 | 3 | 1.0 |
| C c single bond | 3 | 3 | 1.0 |
| Silicon-oxygen (Si-O) | 3 | 3 | 1.0 |
| Siloxane (Si-O-Si) | 2 | 2 | 1.0 |
| Silicon (Si) | 2 | 2 | 1.0 |
| Hydrogen bond | 2 | 2 | 1.0 |
| Aromatic ring | 2 | 2 | 1.0 |
| Carbohydrate | 2 | 0 | 1.0 |
| Silicon nitrogen | 1 | 1 | 1.0 |
| Lignin | 1 | 1 | 1.0 |
| Perchlorate | 1 | 1 | 1.0 |
| Sulfonate | 1 | 1 | 1.0 |
| Borate | 1 | 1 | 1.0 |
| C-S single bond | 1 | 1 | 0.8 |
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 |
|---|---|---|---|
| Cellulose | 1162, 1735, 1650 | Acetate, Methacrylate, C-O single bond | 1 |
| collagen | 1162, 1408, 1660 | 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 1162 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
-
Alkyl C-H confidence 1.0
“The Raman spectrum of PANI that consists cm-1 of peaks at 1162, 1244, 1348, 1482, 1598 and 1609 corresponds to the in-plane C-H bending of the benzeC-N+ noid/quinoid rings, the weak C-N stretching mode, stretching, C=C stretching of the ben”
Gebreegziabher 等 - 2020 - Polyaniline-graphene quantum dots (PANI-GQDs) hybr DOI: 10.1007/s42823-019-00064-6 -
Acetate confidence 1.0
“Shifting of bands in this region is due to interactions between the charged functional groups of the C-O stretching band and the C-O-H group band from 1162 cm-1 (κ-carrageenan) to 1151 cm-1 (κ-carrageenan/starch 2:1) that can be related to”
Preparation and Characterization of Super-Absorbing Gel Formulated from -Carrageenan–Potato Peel Starch Blended Polymers DOI: 10.3390/polym13244308 -
Alkyl C-H confidence 1.0
“The peak for C-O-C (1248 cm-1 ascribable to the deformation of the C-H rocking Meanwhile, the peaks at 1161.72, 1104.35, and 1094.86”
Characterization of cellulose extracted from oil palm empty fruit bunch DOI: 10.1063/1.4931295 -
Alkyl C-H confidence 1.0
“The peak at 1162 is associated with to C-H stretching [30].”
Application of a Low-Cost Cellulose-Based Bioadsorbent for the Effective Recovery of Terbium Ions from Aqueous Solutions DOI: 10.3390/met10121641 -
Hydroxyl (O-H) confidence 1.0
“intensity was found at wavenumbers 1161.52 and 1118.47 However, the cm-1 compound class observed was different at these two peaks where 1161.52 indicates cm-1 tertiary alcohol, meanwhile, 1118.47 represents secondary alcohol.”
Characterization of Malaysian Jatropha Seed Oil and Discovering the Process of Powdered Jatropha Leaves DOI: 10.3390/pr10122577 -
Acetate confidence 1.0
“The bands at 1162, 1115, 1058 and 570 L.V.A.Gurgeletal./IndustrialCropsandProducts36(2012)560-571 asymmetric C-O-C bridge stretching, anhydroglucopyranose ring, involved in the main decomposition step of the cellulose residues.”
Characterization of depolymerized residues from extremely low acid hydrolysis (ELA) of sugarcane bagasse cellulose: Effects of degree of polymerization, crystallinity and crystallite size on thermal decomposition DOI: 10.1016/j.indcrop.2011.11.009 -
C-O single bond confidence 1.0
“3of14 cm-1 lower ratio of the 1162 and 1172 bands (C-OH stretches of hydroxyproline) were observed in the cardiomyopathic tissue.”
Chrabaszcz 等 - 2020 - Tracking Extracellular Matrix Remodeling in Lungs DOI: 10.3390/molecules25010236 -
Alkyl C-H confidence 1.0
“is associated with CH2 bending of 160∘ C for removal from switchgrass using [EMIM]COOH at 1162cm-1”
Dong 等 - 2015 - An Efficient Process for Pretreatment of Lignocell DOI: 10.1155/2015/978983
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