What absorbs at 1126 cm⁻¹ in an FTIR spectrum?
A band near 1126 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 1126 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) | 6 | 3 | 1.0 |
| Methacrylate | 6 | 3 | 1.0 |
| C-O single bond | 6 | 3 | 1.0 |
| Acetate | 6 | 3 | 1.0 |
| Hydroxyl (O-H) | 2 | 2 | 1.0 |
| Carboxyl (COOH) | 2 | 2 | 1.0 |
| Alkyl C-H | 2 | 1 | 1.0 |
| C c single bond | 2 | 1 | 1.0 |
| Metal hydroxyl | 1 | 1 | 1.0 |
| Sulfate (SO4) | 1 | 1 | 1.0 |
| Metal oxygen | 1 | 1 | 1.0 |
| Secondary amine | 1 | 1 | 1.0 |
| C n single bond | 1 | 1 | 1.0 |
| Amide | 1 | 1 | 1.0 |
| Phosphate (PO4) | 1 | 1 | 1.0 |
| Fatty acid | 1 | 1 | 1.0 |
| Silanol (Si-OH) | 1 | 1 | 1.0 |
Ranking reflects accumulated literature evidence, not a single fixed rule. Always confirm against your sample context.
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 1126 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
-
Silanol (Si-OH) confidence 1.0
“The subtracted spectrum revealed an increase in the shoulder bands at 1126 and cm(cid:2)1, cm(cid:2)1, 1040 in addition to the silanol band at 900-920 while a decrease in the intensity of methoxy bands could be observed”
Structural studies of alkoxysilyl-functionalised ionic liquid and its application in a hybrid electrochromic device DOI: 10.1016/j.materresbull.2012.08.036 -
confidence 1.0
“The band at 1126 was due to the et al., 2018).”
Green synthesis of magnetite nanoparticles using Lathyrus sativus peel extract and evaluation of their catalytic activity DOI: 10.1016/j.clet.2021.100117 -
C c single bond confidence 1.0
“The bands at around 1126 C-C animal fat samples, chicken oil displayed the lowest concentration of were associated with the stretching (Berhe et al., 2016;”
Comparison and chemical structure-related basis of species discrimination of animal fats by Raman spectroscopy using near-infrared and visible excitation lasers DOI: 10.1016/j.lwt.2020.110105 -
Acetate confidence 1.0
“Literature Substance cm-1 1126 1125 C-O (oxygen stretching) [57]”
Selected Physicochemical Properties of Lyophilized Hydrogel with Liposomal Fraction of Calcium Dobesilate DOI: 10.3390/ma11112143 -
Carboxyl (COOH) confidence 1.0
“show the presence of the lactate band at 1126 Interestingly,”
Rapid approach to analyze biochemical variation in rat organs by ATR FTIR spectroscopy DOI: 10.1016/j.saa.2013.09.131 -
Phosphate (PO4) confidence 1.0
“AC 720cm-1 748cm-1are to associated with the stretching vibration of bridging oxygen cm-1 [17,21].The bands at around 790-815 are due to symmetric stretching vibrations of Pcm-1 1012cm-1 O-P rings [22] .The bands lie around at 1000 to are a”
Yaacob 等 - 2018 - Comprehensive study on compositional modification DOI: 10.1016/j.solidstatesciences.2018.05.006 -
confidence 1.0
“Sci.2023,13,8541 8of12 Na2SO4/SiO2 with a spectrum showing symmetric tension vibrations at 617 y 1126 cm-1 Na2SO4/SiO2 with a spectrum showing symmetric tension vibrations at 617 y 1126 cm-1 corresponding to S-O bonds.”
Benito 等 - 2023 - Catalytic Evaluation of Hafnium Modified SiO2 for DOI: 10.3390/app13148541 -
Acetate confidence 1.0
“cm-1 cm-1 Resin-specific bands, such as 2918 CH 2-stretching, 1460 CH bending, 1126 C-O Resin-specific bands, such as 2918 cm-1 CH2-stretching, 1460 cm-1 CH2 bending, 1126 cm-1 C-O 2 cm-1 ether bond, and 746 CH rockings appear most intensiv”
Development of Bioepoxy Resin Microencapsulated Ammonium-Polyphosphate for Flame Retardancy of Polylactic Acid DOI: 10.3390/molecules24224123
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.