What absorbs at 480 cm⁻¹ in an FTIR spectrum?
A band near 480 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 480 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 (Si) | 8 | 7 | 1.0 |
| Metal oxygen | 7 | 7 | 1.0 |
| Silicon-oxygen (Si-O) | 7 | 6 | 1.0 |
| Alkyl C-H | 5 | 3 | 1.0 |
| Siloxane (Si-O-Si) | 2 | 2 | 1.0 |
| Silicon silicon | 2 | 2 | 1.0 |
| Methoxy (OCH3) | 2 | 1 | 1.0 |
| Methacrylate | 2 | 1 | 1.0 |
| Acetate | 2 | 1 | 1.0 |
| C-O single bond | 1 | 1 | 1.0 |
| C c single bond | 1 | 1 | 1.0 |
| Fluorine (C-F) | 1 | 1 | 1.0 |
| Metal sulfur | 1 | 1 | 1.0 |
| Phosphate (PO4) | 1 | 1 | 1.0 |
| Carbohydrate | 1 | 1 | 1.0 |
| Hydroxyl (O-H) | 1 | 1 | 1.0 |
| Methyl | 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 |
|---|---|---|---|
| ZnO | 480, 1400, 3430 | Metal oxygen, Alkyl C-H | 1 |
| copper oxide | 480, 624, 1686 | Metal oxygen, Alkyl C-H | 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 480 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
-
Silicon silicon confidence 1.0
“Before annealing treatments, some signature of the presence of Si-Si bonds (weak band centered at 480 cm-1 assigned to the amorphous silicon phase) are present in the spectrum of the as-grown material.”
Benyahia 等 - 2017 - Evolution of Optical and Structural Properties of DOI: 10.4028/www.scientific.net/JNanoR.49.163 -
Alkyl C-H confidence 1.0
“to 2860 CH band, the region between 900 and 1200 cm-1 In all sites, component loadings showed that the decalcifi - that includes the aromatic C-H band, and a band near 480 cation increased absorption at the CH bending region between (Fig.”
Calderon 等 - 2011 - Chemical Differences in Soil Organic Matter Fracti DOI: 10.2136/sssaj2009.0375 -
Silicon silicon confidence 1.0
“In Raman spectrum, for amorphous phase and crystalline phase, the Si-Si TO phonon mode occurs at about 480 cm-1 and 520 cm-1, respectively.”
Chen 等 - 2014 - Effect of Deposition Power on the Structure Proper DOI: 10.4028/www.scientific.net/AMM.442.116 -
Metal oxygen confidence 1.0
“[37] specified vibrational peaks for Cu-O from 480 to Fig.”
Green Fabrication of Copper Oxide Nanoparticles: A Comparative Antibacterial Study Against Gram-Positive and Gram-Negative Bacteria DOI: 10.1007/s13369-021-05767-5 -
confidence 1.0
“The intense band situated at about 480 of wavelength is assigned to the characteristic features of the Cu-O vibrations and confirmed the formation of CuO NPs successfully [23].”
Jing 等 - 2019 - Biosynthesis of copper oxide nanoparticles and the DOI: 10.1016/j.jphotobiol.2019.111557 -
Silicon (Si) confidence 1.0
“The TO mode at 480 cm-1 is an outstanding characteristic of the Raman spectrum of a-Si: H(B), which originates from the short-range order of an amorphous network [37].”
Study of boron doped amorphous silicon lightly hydrogenated prepared by DC magnetron sputtering for infrared detectors applications DOI: 10.1016/j.infrared.2020.103556 -
Hydroxyl (O-H) confidence 1.0
“These bands can be assigned to the other two OD stretching (480) OH mode bands, which, accordingly to crystal structure data, are 14 450 450 involved into a chain of three H-bonds.”
Rozenberg 等 - 2004 - Low temperature FTIR spectra and hydrogen bonds in DOI: 10.1016/j.saa.2003.12.013 -
Metal oxygen confidence 1.0
“In Fig 5, the band cm-1 located at 480 is correlated to metal oxide bond”
Saini 等 - 2013 - Structural and Optical Properties of ZnO Nanoparti DOI: 10.1063/1.4810170
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