What absorbs at 499 cm⁻¹ in an FTIR spectrum?
A band near 499 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 499 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 |
|---|---|---|---|
| Phosphate (PO4) | 1 | 1 | 1,0 |
| Nitro (NO2) | 1 | 1 | 1,0 |
| Ester | 1 | 1 | 1,0 |
| Metalloid oxygen | 1 | 1 | 0,9 |
| Metal oxygen | 1 | 1 | 0,9 |
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 |
|---|---|---|---|
| glass | 499, 1100, 1075 | Metalloid oxygen | 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 499 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
-
Ester affidabilità 1,0
“Substituted 2Hstretching of the CNC fragment of a The 498 515 azirines with a methyl ester group have characteristic intense intensity of this band is low, and all other bands predicted by 499 516”
Lopes 等 - 2011 - Photochemistry and Vibrational Spectra of Matrix-I DOI: 10.1021/jp110705c -
Nitro (NO2) affidabilità 1,0
“base peak is centered at m/z 499.0753, corresponding to the anticipated nitrite complex [FeIII(NO 2)(N3PyS)]+ and exhibiting the theoretically predicted isotope pattern (see Supporting Information).”
Photoinitiated Reactivity of a Thiolate-Ligated, Spin-Crossover Nonheme {FeNO}7 Complex with Dioxygen DOI: 10.1021/jacs.5b12741. -
Phosphate (PO4) affidabilità 1,0
“The bands at 500-650 and 460 are due to asymmetric and symmetric Catalysts2021,11,499 3of11 cm-1 bending P-O vibration, respectively [30].”
Rapid Synthesis of Asymmetric Methyl-Alkyl Carbonates Catalyzed by -KMgPO4 in a Sealed-Vessel Reactor Monowave 50 DOI: 10.3390/catal11040499 -
Metal oxygen affidabilità 0,9
“Same as above; peak shift range includes 499.4 cm-1.”
Er3+:Nd3+ concentration dependent spectral features of lithium-niobate-tellurite amorphous media DOI: 10.1016/j.jnoncrysol.2016.04.002
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