What absorbs at 802 cm⁻¹ in an FTIR spectrum?
A band near 802 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 802 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.
Possíveis atribuições de grupos funcionais
| Grupo funcional | Fatos de suporte | Fontes citadas | Maior confiança |
|---|---|---|---|
| Alkyl C-H | 5 | 5 | 1,0 |
| Aromatic ring | 3 | 3 | 1,0 |
| Siloxane (Si-O-Si) | 2 | 2 | 1,0 |
| Ring structure | 2 | 2 | 1,0 |
| Thiocarbonyl | 1 | 1 | 1,0 |
| Metal oxygen | 1 | 1 | 1,0 |
| C c single bond | 1 | 1 | 1,0 |
| N n 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 |
| Hydrogen bond | 1 | 1 | 1,0 |
| Chlorine | 1 | 1 | 1,0 |
| Hydroxyl (O-H) | 1 | 1 | 1,0 |
| Silanol (Si-OH) | 1 | 1 | 1,0 |
| Silicon carbon | 1 | 1 | 1,0 |
| Alkene (C=C) | 1 | 1 | 1,0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 0,9 |
| Silicon (Si) | 1 | 1 | 0,8 |
A classificação reflete a evidência acumulada da literatura, não uma única regra autoritária. Sempre confirme com o contexto da sua amostra.
Possible materials
| Material | Picos de suporte | Overlapping groups | Fontes citadas |
|---|---|---|---|
| polyaniline | 802, 1565, 1570 | Aromatic ring, Alkyl C-H, Ring structure | 1 |
| gelatin | 802, 1652, 3300 | Alkyl C-H | 1 |
| PANI | 802, 2930, 1300 | Aromatic ring, Alkyl C-H, Ring structure | 1 |
| silver nanoparticles | 802, 1636, 1631 | 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 802 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.
Literatura por trás destas atribuições
-
Alkene (C=C) confiança 1,0
“LLM confirmed rule peak-group candidate”
Green Fabrication of Copper Oxide Nanoparticles: A Comparative Antibacterial Study Against Gram-Positive and Gram-Negative Bacteria DOI: 10.1007/s13369-021-05767-5 -
Alkyl C-H confiança 1,0
“The absorbance peaks at 802 which to There is liberation of reactive hydrogen in C-H represents the aromatic ring vibration, indicate the the keto form of the rosemarinic acid to form an”
Jayaseelan 和 Rahuman - 2012 - Acaricidal efficacy of synthesized silver nanopart DOI: 10.1007/s00436-011-2559-1 -
Aromatic ring confiança 1,0
“The peak at 801.6 is attributed to the out-of-plane deformation vibration of the para-substituted benzene ring.”
Li 等 - 2013 - Synthesis and Microwave Absorption Characteristics DOI: 10.4028/www.scientific.net/AMM.327.53 -
Silicon carbon confiança 1,0
“The bands at 802 bonds, including (a) out-ofvibrational modes of Si-CH 3 cm-1 ± are assigned to the bond-bending and bondstretching vibration at 2976 and 459 phase or asymmetric CH 3”
Rios 等 - 2011 - Characterisation of hybrid xerogels synthesised in DOI: 10.1007/s10450-011-9331-9 -
Silanol (Si-OH) confiança 1,0
“line This observation is accompanied with the reduction of network SiO band at 802 2 cm-1 Meanwhile, the Si-OH peak at 981 showed the increased of intensity in silica synthesized using 1% and 2% of gelatin concentration.”
The effect of gelatin as pore expander in green synthesis mesoporous silica for methylene blue adsorption DOI: 10.1038/s41598-022-19615-5 -
Aromatic ring confiança 1,0
“Besides, the peaks near to 802 was benzenoid ring of PANI and the attributed to the out-of-plane bending of C-H.”
Properties of conductive PANI fabricated using different dopant acids and molar ratios DOI: 10.1063/5.0015755 -
Alkyl C-H confiança 1,0
“LLM confirmed rule peak-group candidate”
Synthesis of Uniform Polyaniline Nanofibers through Interfacial Polymerization DOI: 10.3390/ma5081487 -
confiança 1,0
“cm-1, shifted downward, while the C-O stretch bond at 1 264.2 and 3 581.7 C=O stretch bond and N=H bend bond at cm-1 cm-1 C-Cl stretch at 802.1 appeared and disappeared, respectively, 2 908.7 IR peaks appeared after activation.”
Adetoro 等 - 2022 - Adsorption and desorption studies of Carica papaya DOI: 10.17159/wsa/2022.v48.i2.3903
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