What absorbs at 805 cm⁻¹ in an FTIR spectrum?
A band near 805 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 805 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 |
|---|---|---|---|
| Silicon-oxygen (Si-O) | 6 | 6 | 1,0 |
| Silicon (Si) | 3 | 3 | 1,0 |
| Siloxane (Si-O-Si) | 3 | 3 | 1,0 |
| Alkyl C-H | 2 | 2 | 1,0 |
| Sulfate (SO4) | 2 | 2 | 1,0 |
| Hydroxyl (O-H) | 2 | 2 | 1,0 |
| Aromatic ring | 1 | 1 | 1,0 |
| Ring structure | 1 | 1 | 1,0 |
| Silicon carbon | 1 | 1 | 1,0 |
| Metal oxygen | 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 |
| Boron nitrogen | 1 | 0 | 0,9 |
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 |
|---|---|---|---|
| SiC | 805, 791, 1136 | Silicon-oxygen (Si-O), Silicon (Si), Siloxane (Si-O-Si) | 1 |
| asphalt | 805, 1600, 1376 | Alkyl C-H | 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 805 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
-
confiança 1,0
“In addition, the bands at 805.22 are occupied by the phosphate group of the binding cm(cid:0) 1 Si-O and the strong stretching silicon group of the binding.”
Biologically-induced synthetic manganese carbonate precipitate (BISMCP) for potential applications in heavy metal removal DOI: 10.1016/j.heliyon.2023.e15919 -
Sulfate (SO4) confiança 1,0
“LLM confirmed rule peak-group candidate”
Fauzi 等 - 2020 - Characterization, Disintegration, and Dissolution DOI: 10.1155/2020/3565931 -
Hydroxyl (O-H) confiança 1,0
“CR occurs at the peak of 1261 1094 1031 804.7 and 667 cm-1, cm-1 cm-1 The absorption peaks at 1261 1094 and 1031 are identified as the bending vibrations of O-H, stretching vibrations of C-O and stretching vibrations of 804.7cm-1 S=O, respe”
Liang 等 - 2017 - Thermo-stability and aging performance of modified DOI: 10.1016/j.matdes.2017.04.060 -
Metal oxygen confiança 1,0
“The cm-1 intense transmittance band at 805 is due to vibrating Figure 6 displays the UV-visible spectra of YVO4:5%Dy, modes of stretching frequency of V-O bonds in YVO Eu (1 mol%, 3 mol%, 5 mol% and 7 mol%) nanophosphor.”
Synthesis and luminescence properties of europium-codoped and dysorium-doped YVO4 nanophosphor for potential applications DOI: 10.1007/s00339-019-2990-1 -
confiança 1,0
“1.0 corresponded to the asymmetric vibration of the siloxane ml/min) to pH = 9 with 150 ml of 3.0 mol/L HNO containcm-1 bond Si-O-Si, and the band at 805 was assigned to the 3”
Adam 等 - 2012 - Liquid Phase Oxidation of Acetophenone over Rice H DOI: 10.1016/S1872-2067(11)60361-6 -
confiança 1,0
“(cid:2)460, vibration patterns of KIT-6 centered at 805, 970, and crystalline emulsion with the crystallization time of 24 h cm(cid:4)1.29 cm(cid:4)1 1080 The adsorption band around 460 represents could be easily assembled using a mesoporou”
Synthesis of ZSM-5/KIT-6 with a tunable pore structure and its catalytic application in the hydrodesulfurization of dibenzothiophene and diesel oil DOI: 10.1039/c8ra05675g -
Silicon carbon confiança 1,0
“5a, top plot) show a distinct (possibly crystalline) cm-1, which corresponds to the transverse optical vibrational mode of SiC, along with a shoulder where peak at 805 cm-1, which corresponds to the lateral optical vibrational mode of SiC [”
Henry 等 - 2018 - Characterization of Ceramic Matrix Composite Degra DOI: 10.1063/1.5031613 -
Hydroxyl (O-H) confiança 1,0
“It also shows reduced absorbance in the 805 and OH deformation vibrations and CO stretching vibrations (phecm-1 gion, which is associated with the sulfate group of the 3,6-anhynols) can be found.”
A novel biodegradable film based on κ‐carrageenan activated with olive leaves extract DOI: 10.1002/fsn3.1554
Tem um espectro com esta banda?
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