What absorbs at 518 cm⁻¹ in an FTIR spectrum?
A band near 518 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 4 cited sources
Quick answer
A band near 518 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.
Possibili assegnazioni di gruppi funzionali
| Gruppo funzionale | Fatti di supporto | Fonti citate | Affidabilità massima |
|---|---|---|---|
| Silicon (Si) | 3 | 3 | 1,0 |
| Metal oxygen | 2 | 2 | 1,0 |
| Silicon silicon | 1 | 1 | 1,0 |
| Phosphorus | 1 | 0 | 1,0 |
| Phosphate (PO4) | 1 | 0 | 1,0 |
La classifica riflette le prove bibliografiche accumulate, non una singola regola autorevole. Conferma sempre nel contesto del tuo campione.
Possible materials
| Materiale | Picchi di supporto | Overlapping groups | Fonti citate |
|---|---|---|---|
| silica | 518, 1100, 1080 | Silicon (Si) | 2 |
| montmorillonite | 518, 1637, 523 | Silicon (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 518 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.
Letteratura dietro queste assegnazioni
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Silicon (Si) affidabilità 1,0
“The pronounced peak around cm-1 518 was observed from the Raman spectrum, characteristic of crystalline silicon.”
Nanostructured Silicon Derived from an Agricultural Residue Bagasse Ash via Magnesiothermic Reduction Method DOI: 10.3390/coatings13020221 -
Silicon (Si) affidabilità 1,0
“tions of SiO4 tetrahedra at 668 and 603 cm-1 (νsSi-O-Si), and 518 and 473 cm-1, due to Sicm-1 cm-1, (ν tions of SiO tetrahedra at 668 and 603 sSi-O-Si), and 518 and 473 due to 4 O-Si and O-Si-O bending vibrations, respectively.”
Phase Composition of Silica Fume—Portland Cement Systems Formed under Hydrothermal Curing Evaluated by FTIR, XRD, and TGA DOI: 10.3390/ma14112786 -
affidabilità 1,0
“In addition, the absorption and 518 cm-1 and 471 cm-1 for Cn-MT2 are attributed to Mg-O-Si and Mg-O bending vibration,”
Qiu 等 - 2020 - Comprehensive Characterization of the Structure an DOI: 10.3390/min10040378 -
Metal oxygen affidabilità 0,9
“Peak at 518 related to Fe-O, Al-O, Fe-Al-O”
Heteropolyacid coupled with cyanoguanidine decorated magnetic chitosan as an efficient catalyst for the synthesis of pyranochromene derivatives DOI: 10.1038/s41598-022-21196-2
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