What absorbs at 1090 cm⁻¹ in an FTIR spectrum?
A band near 1090 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 1090 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 |
|---|---|---|---|
| Silicon-oxygen (Si-O) | 17 | 16 | 1.0 |
| Alkyl C-H | 14 | 14 | 1.0 |
| C-O single bond | 14 | 14 | 1.0 |
| Methacrylate | 14 | 14 | 1.0 |
| Acetate | 14 | 14 | 1.0 |
| Methoxy (OCH3) | 13 | 13 | 1.0 |
| Siloxane (Si-O-Si) | 11 | 11 | 1.0 |
| Silicon (Si) | 10 | 9 | 1.0 |
| Amide | 9 | 9 | 1.0 |
| Phosphate (PO4) | 9 | 6 | 1.0 |
| Hydroxyl (O-H) | 7 | 7 | 1.0 |
| Secondary amine | 6 | 6 | 1.0 |
| C n single bond | 6 | 6 | 1.0 |
| Phosphorus | 4 | 2 | 1.0 |
| Carboxyl (COOH) | 3 | 3 | 1.0 |
| N h | 3 | 3 | 1.0 |
| Ester | 2 | 2 | 1.0 |
| C=n | 2 | 2 | 1.0 |
| Amino acid | 2 | 2 | 1.0 |
| Carbonate | 2 | 1 | 1.0 |
| Ketone | 1 | 1 | 1.0 |
| Carbonyl (C=O) | 1 | 1 | 1.0 |
| Phospholipid | 1 | 1 | 1.0 |
| Carbohydrate | 1 | 1 | 1.0 |
| Silicon hydride | 1 | 1 | 1.0 |
| Water (H2O) | 1 | 1 | 1.0 |
| S eq o | 1 | 1 | 1.0 |
| Aromatic ring | 1 | 1 | 1.0 |
| Nucleic acid | 1 | 1 | 1.0 |
| Nitrogen heterocycle | 1 | 1 | 1.0 |
| Silanol (Si-OH) | 1 | 1 | 1.0 |
| Sulfate (SO4) | 1 | 1 | 1.0 |
| Hydrogen bond | 1 | 1 | 1.0 |
| Fluorine (C-F) | 1 | 1 | 0.9 |
| Anhydride | 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 |
|---|---|---|---|
| chitosan | 1090, 1650, 1655 | Alkyl C-H, Methacrylate, C-O single bond | 1 |
| silica | 1090, 1100, 1080 | Silicon-oxygen (Si-O), Alkyl C-H, Methacrylate | 1 |
| graphene oxide | 1090, 1150, 3400 | Methacrylate, C-O single bond, Alkyl C-H | 1 |
| DNA | 1090, 1712, 1660 | Methacrylate, C-O single bond | 1 |
| cells | 1090, 970, 1741 | Alkyl C-H, 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 1090 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
-
Amino acid confidence 1.0
“A peak at 1090 in FTIR not correctly understand the mechanism which can explain the band do spectra change of amino acid added FTIR-GONP corresponds to amide forin linear response for different amino acids.”
Fluorometric estimation of amino acids interaction with colloidal suspension of FITC functionalized graphene oxide nanoparticles DOI: 10.1016/j.apsusc.2016.11.070 -
Hydroxyl (O-H) confidence 1.0
“alcohol bands (appearing at about 1090 also occurred simultaneously during the latter stage of cm21) (iv) Bands due to acetic acid (1013, 620 and 458”
De 等 - 2000 - Hydrolysis-condensation reactions of TEOS in the p DOI: 10.1039/B003221M -
Phosphate (PO4) confidence 1.0
“LLM confirmed rule peak-group candidate”
Jaber 和 Kovacs - 2019 - Preparation and synthesis of hydroxyapatite bio-ce DOI: 10.14382/epitoanyag-jsbcm.2019.18 -
Amide confidence 1.0
“change in % transmittance at wavenumbers corresponding to bonds associated with N cm-1, cm-1, atoms (N-H bending/stretching 1090 C-N stretching 1359 and N-H rocking 895 cm-1) in CS-GNP.”
Jaiswal 和 Dhayal - 2020 - Preparation of 2D coatings of functionally graded DOI: 10.1016/j.matchemphys.2020.122663 -
N h confidence 1.0
“N-H twisting and rocking”
A novel study for producing complexed and encapsulated nutrients at nanometric scale to enhance plant growth DOI: 10.1038/s41598-023-37607-x -
Phosphate (PO4) confidence 1.0
“LLM confirmed rule peak-group candidate”
A new approach to studying the effects of ionising radiation on single cells using FTIR synchrotron microspectroscopy DOI: 10.1016/j.radphyschem.2013.03.037 -
confidence 1.0
“The peak at about 1090 Si-O tributed to the hydrogen-bonded stretching vibration.”
Lu 和 Mi - 2005 - Characterization of the interfacial interaction be DOI: 10.1021/ma0486896 -
Amino acid confidence 1.0
“DL-histidine in H 2O revealed two bands at 1090 spectrum of cm-1 and 1106 (Figure 4e, thin line), which were assigned nated and an imidazolium form is produced (Figure 1c).”
Noguchi 等 - 1999 - Structure of a histidine ligand in the photosynthe DOI: 10.1021/bi990631
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