What absorbs at 817 cm⁻¹ in an FTIR spectrum?
A band near 817 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 817 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 |
|---|---|---|---|
| Aromatic ring | 5 | 4 | 1,0 |
| Methoxy (OCH3) | 4 | 4 | 1,0 |
| Methacrylate | 4 | 4 | 1,0 |
| C-O single bond | 4 | 4 | 1,0 |
| Acetate | 4 | 4 | 1,0 |
| Alkyl C-H | 4 | 3 | 1,0 |
| C c single bond | 3 | 2 | 1,0 |
| Alkene (C=C) | 2 | 1 | 1,0 |
| Hydrogen bond | 2 | 1 | 1,0 |
| Phosphorus | 1 | 1 | 1,0 |
| Phosphate (PO4) | 1 | 1 | 1,0 |
| Ring structure | 1 | 1 | 1,0 |
| Amide | 1 | 1 | 1,0 |
| N h | 1 | 1 | 1,0 |
| Carboxyl (COOH) | 1 | 1 | 1,0 |
| Nitrogen heterocycle | 1 | 1 | 1,0 |
| N-O bond | 1 | 1 | 1,0 |
| Hydroxyl (O-H) | 1 | 1 | 1,0 |
| Borate | 1 | 1 | 1,0 |
| Lignin | 1 | 1 | 1,0 |
| Boron nitrogen | 1 | 1 | 0,9 |
| Sulfur heterocycle | 1 | 0 | 1,0 |
| C-S single bond | 1 | 0 | 1,0 |
| Silicon (Si) | 1 | 0 | 1,0 |
| Siloxane (Si-O-Si) | 1 | 0 | 1,0 |
| Silicon-oxygen (Si-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 |
|---|---|---|---|
| ZnO | 817, 1400, 3430 | Methacrylate, C-O single bond, Methoxy (OCH3) | 1 |
| Fe2O3 | 817, 1130, 1631 | Methacrylate | 1 |
| lignin | 817, 1035, 1510 | Methacrylate, C-O single bond, Aromatic ring | 1 |
| PE | 817, 1414, 1700 | Methacrylate, Aromatic ring, Methoxy (OCH3) | 1 |
| PP | 817, 1700, 1043 | Methacrylate, Aromatic ring, Methoxy (OCH3) | 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 817 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
-
Aromatic ring confiança 1,0
“Weak peak appears at 817 in BA-Coir/(Py-Acetone) and Coir-BA (Py-Acetone)-C-BPO due to two adjacent aromatic Ccm-1 H bending vibration of lignin component.”
Rout 等 - 2017 - A green approach to produce silver nano particles DOI: 10.1016/j.surfin.2017.03.004 -
Alkyl C-H confiança 1,0
“As regards the broad band close to 568 cm-1, cm-1, cm-1, cm-1, cm-1 1087 2358 1191 1448 817 cm-1 and 3200 were attributed to stretching vibrations of C-H, C O, B-O and O-H bonds, respectively.”
Zhang 等 - 2019 - Synthesis of TiB2 Powders with Hexagonal Morpholog DOI: 10.1166/jnn.2019.16750 -
Acetate confiança 1,0
“some peaks, situated at 817 and 859 were assigned to the cm-1 (xi) C-O bond from cyclohexane [33];”
Bita 等 - 2023 - Diester Chlorogenoborate Complex A New Naturally DOI: 10.3390/inorganics11030112 -
C c single bond confiança 1,0
“881 sidic links, characteristic of polysaccharides structure ring 852 ------ Stretching C-C of ethyl 817”
Flores-Hernandez 等 - 2021 - Synthesis of a Biodegradable Polymer of Poly (Sodi DOI: 10.3390/polym13040504 -
N-O bond confiança 1,0
“structure.18 WS, initially no peaks were detected at 817 however, lignin-50 °C, Figure 6 shows the SEM images of the wt % WS after pyrolysis of WS at 300, 500, 700, and 900 the different foams fabricated at temperatures, for example, Figure”
Gupta 等 - 2020 - On the Design of Novel Biofoams Using Lignin, Whea DOI: 10.1021/acsomega.0c00721 -
C c single bond confiança 1,0
“The band of 817.23 was known as the stretching mode of C-C.”
Harati 等 - 2022 - Enhanced photocatalytic activity of Fe2O3@ZnO deco DOI: 10.1007/s40201-021-00758-y -
Acetate confiança 1,0
“the spectra of the silicon substrate, while that for PMMA on the klarite surface was seen at cm-1 cm-1 cm-1 622 due to C-C-O stretching, 817 (C-O-C symmetric stretching), 1000 E P”
Kundu 等 - 2021 - Identification and removal of microand nano-plas DOI: 10.1016/j.cej.2021.129816. -
Alkyl C-H confiança 1,0
“the 809-, 817-, 809-, 820-cm-1 , 809-, 817-, and 820-cm-1 peaks are δCH (out-of-plane deformation) of the triazine compound;”
Li 等 - 2019 - Blends of Cyanate Ester and Phthalonitrile-Polyhed DOI: 10.3390/polym11010054
Tem um espectro com esta banda?
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