What absorbs at 1113 cm⁻¹ in an FTIR spectrum?
A band near 1113 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 1113 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 |
|---|---|---|---|
| Methoxy (OCH3) | 9 | 9 | 1.0 |
| Methacrylate | 9 | 9 | 1.0 |
| C-O single bond | 9 | 9 | 1.0 |
| Acetate | 9 | 9 | 1.0 |
| Silicon-oxygen (Si-O) | 7 | 7 | 1.0 |
| Amide | 4 | 4 | 1.0 |
| Silicon (Si) | 4 | 4 | 1.0 |
| Alkyl C-H | 3 | 3 | 1.0 |
| Hydroxyl (O-H) | 3 | 3 | 1.0 |
| Secondary amine | 3 | 3 | 1.0 |
| C n single bond | 3 | 3 | 1.0 |
| Siloxane (Si-O-Si) | 2 | 2 | 1.0 |
| Nitrogen heterocycle | 2 | 2 | 1.0 |
| Amino acid | 2 | 1 | 1.0 |
| Lignin | 1 | 1 | 1.0 |
| Nucleic acid | 1 | 1 | 1.0 |
| Phosphorus | 1 | 1 | 1.0 |
| Phosphate (PO4) | 1 | 1 | 1.0 |
| Carbohydrate | 1 | 1 | 1.0 |
| Carbonyl (C=O) | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Perchlorate | 1 | 1 | 0.9 |
| Alkene (C=C) | 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 |
|---|---|---|---|
| polyimide | 1113, 1720, 1778 | Methacrylate, Acetate | 1 |
| GO | 1113, 1720, 1182 | Methacrylate, Acetate, C-O single bond | 1 |
| RGO | 1113, 2358, 2930 | 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 1113 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
“1074 stretching 1113 C-H wagging at benzoic ring C-N stretching in imidazole ring and C-C stretching between 1258”
Degradation of Losartan Potassium Highlighted by Correlated Studies of Photoluminescence, Infrared Absorption Spectroscopy and Dielectric Spectroscopy DOI: 10.3390/pharmaceutics14112419 -
Amide confidence 1.0
“cm-1 and 1717 (asymmetric and symmetric stretching vibra- = = cm-1 tions of O C-N-C O of cyclic imide groups), 1375 (C-N cm-1 cm-1 vibration), 1113 The polyimide films prepared were transparent and flex- (imide ring deformation) and 738 μ.”
Purushothaman 和 Bilal - 2014 - Development and characterization of homo, co and t DOI: 10.1515/polyeng-2013-0167 -
Amide confidence 1.0
“The C-N group of polymer 2 cm-1 associated to the asymmetric stretching vibration is assigned at 1113 and the vibration”
Electrospinning Process Parameters Dependent Investigation of TiO2 Nanofibers DOI: 10.1016/j.rinp.2018.08.054 -
Silicon (Si) confidence 1.0
“The peaks at 1113 assigned to Si-O stretching vibration, are not associated with n”
Swain - 2022 - Process Dependent Strain Behaviour, Fractal Analys DOI: 10.21203/rs.3.rs-374154/v1 -
Alkyl C-H confidence 1.0
“1113cm-1 and1149cm-1 areherebyassignedto1139cm-1 According to DFT calculations, there are 14 C-H stretchand 1164cm-1 ing vibrations in different combinations between 3000 and , respectively, according to Table 1 and relative PED”
Ullah 等 - 2016 - Fourier Transform Infrared Spectroscopy of Bisphe DOI: 10.1155/2016/2073613 -
confidence 1.0
“absorption peaks at430, 496, and 677 are attributedto 1113cm-1 FTIR spectra of all gemstones under investigation are Si-O bending vibrations, while the peak at is”
Ahmad 等 - 2021 - Spectroscopic Analysis for Harnessing the Quality DOI: 10.1155/2021/6629640 -
Silicon-oxygen (Si-O) confidence 1.0
“The bands and fluoride adsorption with a percentage removal of 86% at pH 750cm-1 in1113cm-1Siareattributed toSi-quartz(asalso 6 and after 120 minutes' contact time resulting in an ad996cm-1 cm-1are O quartz), whereas and 910 the vibrations”
Annan 等 - 2021 - Synthesis and Characterization of Modified Kaolin- DOI: 10.1155/2021/6679422 -
Hydroxyl (O-H) confidence 1.0
“1113 For RGO, the -OH vibrations peak is almost cm-1 disappeared and an intense peak at 1557 appeared, corresponding to the C=C stretching in the graphitic ring”
Reduced graphene oxide-intercalated graphene oxide nano-hybrid for enhanced photoelectrochemical water reduction DOI: 10.1007/s40097-019-00324-x
Have a spectrum with this band?
Upload your FTIR spectrum and get a full interpretation report — peak assignments with literature citations, library matches, and a literature-backed analysis — in seconds.