What absorbs at 809 cm⁻¹ in an FTIR spectrum?
A band near 809 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
Resposta rápida
A band near 809 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 |
|---|---|---|---|
| Methacrylate | 4 | 3 | 1,0 |
| Acetate | 4 | 3 | 1,0 |
| Alkyl C-H | 4 | 3 | 1,0 |
| Methoxy (OCH3) | 3 | 3 | 1,0 |
| C-O single bond | 3 | 3 | 1,0 |
| Silicon-oxygen (Si-O) | 2 | 2 | 1,0 |
| Metal oxygen | 2 | 2 | 1,0 |
| Amide | 2 | 1 | 1,0 |
| C-S single bond | 1 | 1 | 1,0 |
| Silicon (Si) | 1 | 1 | 1,0 |
| Aromatic ring | 1 | 1 | 1,0 |
| Nitrogen heterocycle | 1 | 1 | 1,0 |
| N h | 1 | 1 | 1,0 |
| Secondary amine | 1 | 1 | 1,0 |
| C n single bond | 1 | 1 | 1,0 |
| Siloxane (Si-O-Si) | 1 | 1 | 1,0 |
| Silicon carbon | 1 | 1 | 1,0 |
| Carbohydrate | 1 | 1 | 0,8 |
| Ketone | 1 | 0 | 1,0 |
| Ester | 1 | 0 | 1,0 |
| Carboxyl (COOH) | 1 | 0 | 1,0 |
| Carbonyl (C=O) | 1 | 0 | 1,0 |
A classificação reflete a evidência acumulada da literatura, não uma única regra autoritária. Sempre confirme com o contexto da sua amostra.
Materiais possíveis
| Material | Picos de suporte | Grupos sobrepostos | Fontes citadas |
|---|---|---|---|
| silica | 809, 1100, 1080 | Alkyl C-H, Methacrylate, Acetate | 1 |
| nanotubes | 809, 1735, 1630 | Alkyl C-H, Methacrylate, Acetate | 1 |
| lignin | 809, 1035, 1510 | Alkyl C-H, Methacrylate, Acetate | 1 |
Os materiais são mostrados apenas quando o mesmo conjunto de literatura suporta esta banda e pelo menos um pico característico adicional.
Lógica do espectro
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 809 cm⁻¹ is usually not enough for material identification by itself.
Uso no mundo real
Este tipo de consulta é comum em identificação de polímeros, triagem de plásticos desconhecidos, solução de problemas de CQ, verificação de materiais reciclados e revisão de atribuição de picos apoiada pela literatura.
Erros comuns
- Tratar uma banda isolada como prova de um material sem verificar pelo menos um ou dois picos de suporte.
- Ignorando sobreposição: vários grupos funcionais podem contribuir próximo ao mesmo número de onda.
- Ignorar a validação quando aditivos, misturas, oxidação ou contaminação podem distorcer o espectro.
Conselho de verificação
Quando a ambiguidade persistir, valide a hipótese com DSC, GC-MS ou TGA, especialmente para misturas, amostras degradadas e polímeros carregados.
Literatura por trás destas atribuições
-
Metal oxygen confiança 1,0
“and iii)the appearanceof newRaman lines at 809 cm-1, 710 and 809 which are attributed to the W-O vibrational mode in WO [28].”
Single-walled carbon nanotubes functionalized with polydiphenylamine as active materials for applications in the supercapacitors field DOI: 10.1016/j.diamond.2012.12.006 -
Silicon carbon confiança 1,0
“Correspond to Si-C bonds.”
Optical and photoelectrochemical properties of nitrogen-doped a-SiC thin films deposited by reactive DOI: 10.1080/2374068X.2021.1890420 -
Metal oxygen confiança 1,0
“10 a-b), peaks at 809, 811 and 812 cm-1 mixtures, MNP-PCP shifted to 814 which assigned to As-O [35].”
Enhanced arsenic (iii) adsorption from aqueous solution by magnetic pine cone biomass DOI: 10.1016/j.matchemphys.2018.09.067 -
confiança 1,0
“The cm-1 intense band at 1069 corresponds to the Si-O-Si symmetric stretching vibration, cm-1 whereas the Si-O-Si anti-symmetric stretching band is observed at 809 [24,25].”
Vibrational spectroscopic study of pure and silica-doped sulfonated poly(ether ether ketone) membranes DOI: 10.1016/j.saa.2014.12.004 -
Alkyl C-H confiança 1,0
“The spectrum of porous graphene nanosheets is represented by the cm-1, cm-1, cm-1 cm-1, peaks at 809 1636 2344 and 3309 resulting from C-H bonding, C=C conjugation, C-N band and N-H extending vibrations.”
An Amperometric Acetylcholine Biosensor Based on Co-Immobilization of Enzyme Nanoparticles onto Nanocomposite DOI: 10.3390/bios13030386 -
Acetate confiança 1,0
“[60] assigned the spectral features of pure chlorogenic acid isomer standards as follows: The peak at cm-1 cm-1 809 was attributed to cyclohexane C-O twisting;”
Durazzo 等 - 2018 - Qualitative Analysis of Traditional Italian Dishes DOI: 10.3390/su10114112 -
confiança 1,0
“ESI-MS molecular-ion peak 809.21, corresponding to H+ + 1H [Zn(L3) ].”
Gusev 等 - 2020 - Synthesis, Photoluminescence and Electrical Study DOI: 10.3390/ma13245698 -
Acetate confiança 1,0
“cm-1) cm-1) 1330-1326 [30], a C-O-C band center position (1025 [31], and C-O-C vibrations lignin, there is a syringyl (S) at 809 cm-1.”
Mesoporous Manganese Oxide/Lignin-Derived Carbon for High Performance of Supercapacitor Electrodes DOI: 10.3390/molecules26237104
Tem um espectro com esta banda?
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