What absorbs at 523 cm⁻¹ in an FTIR spectrum?
A band near 523 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 523 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 |
|---|---|---|---|
| Metal oxygen | 5 | 4 | 1.0 |
| Silicon-oxygen (Si-O) | 4 | 4 | 1.0 |
| Silicon (Si) | 2 | 2 | 1.0 |
| Siloxane (Si-O-Si) | 2 | 2 | 1.0 |
| Carbohydrate | 1 | 1 | 1.0 |
| N h | 1 | 1 | 1.0 |
| N-O bond | 1 | 1 | 1.0 |
| Methoxy (OCH3) | 1 | 1 | 1.0 |
| Methacrylate | 1 | 1 | 1.0 |
| C-O single bond | 1 | 1 | 1.0 |
| Acetate | 1 | 1 | 1.0 |
| Carbon bromine | 1 | 1 | 0.9 |
| Metal hydroxyl | 1 | 1 | 0.8 |
| Metal oxo | 1 | 1 | 0.7 |
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 |
|---|---|---|---|
| montmorillonite | 523, 1637, 1743 | Silicon-oxygen (Si-O), Silicon (Si) | 2 |
| Silica | 523, 1100, 1080 | Silicon-oxygen (Si-O), Silicon (Si), Siloxane (Si-O-Si) | 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 523 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
-
Acetate confidence 1.0
“cm-1 cm-1 Si\\O (between 1622 and 1606 and is at 625 The two bands at 523 and 460 are asfor different composites), due to the C_O cribed to Si-O-Si andAl-O-Si bendingvibrations.”
Synthesis of montmorillonite/chitosan/ammonium acrylate composite and its potential application in river water flocculation DOI: 10.1016/j.ijbiomac.2020.08.022 -
N-O bond confidence 1.0
“However, they undergo decomposition at high 523cm-1 presence at temperature, and there will be no peak observed for the nitrate group.”
Down-conversion characteristics of Eu3+ doped M2Y2Si2O9 (M = Ba, Ca, Mg and Sr) nanomaterials for innovative solar panels DOI: 10.1016/j.pnsc.2019.07.003 -
confidence 1.0
“The peak at 523 is related to the irregular deformation of C-I”
Investigation of Hemp and Flax Fiber-Reinforced EcoPoxy Matrix Biocomposites: Morphological, Mechanical, and Hydrophilic Properties DOI: 10.3390/polym14214530 -
confidence 1.0
“cm-1 cm-1, 1605 and 3383-3601 being assigned to the vibrational modes of the deformation IR bands of PTA situated at 523 cm-1, 594 cm-1, 797 cm-1, 891 cm-1, 982 cm-1, 1080 cm-1, 1605 (O corresponds to corner oxygen atoms), W-O e-W stretchin”
The Photoluminescence and Vibrational Properties of Black Phosphorous Sheets Chemically/Electrochemically Functionalized in the Presence of Diphenylamine DOI: 10.3390/polym14214479 -
confidence 1.0
“140 The absorption bands at 523 and 468 cm-1 belong to the bending vibrations of the Si-O-Al 141”
Optimization of the Pentachlorophenol Adsorption by Organo-Clays Based on Response Surface Methodology DOI: 10.3390/ma15207169 -
confidence 1.0
“the bands at 523 and 470 appear due to Al-O-Si 729 Investigation of thermal and catalytic degradation”
Filip 等 - 2013 - Investigation of thermal and catalytic degradation DOI: 10.2478/s11532-013-0202-y -
Silicon-oxygen (Si-O) confidence 1.0
“(δ tetrahedral units at 925 and 878 and symmetric s) and antisymmetric as) bendtetrahedral units at 925 and 878 cm-1, and symmetric (δs) and antisymmetric (δas) bending cm-1, ing vibrations of O-Si-O at 523 and 450 respectively.”
Phase Composition of Silica Fume—Portland Cement Systems Formed under Hydrothermal Curing Evaluated by FTIR, XRD, and TGA DOI: 10.3390/ma14112786 -
Metal oxygen confidence 0.9
“Same band as above.”
Urea combustion synthesis of nano-structure bimetallic perovskite FeMnO3 and mixed monometallic iron manganese oxides: effects of preparation parameters on structural, opto-electronic and photocatalytic activity for photo-degradation of Basic Blue 12 DOI: 10.1007/s10854-017-6568-4
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