What absorbs at 844 cm⁻¹ in an FTIR spectrum?
A band near 844 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 844 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 (Si) | 1 | 1 | 1,0 |
| Ring structure | 1 | 1 | 1,0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1,0 |
| Oxygen heterocycle | 1 | 1 | 1,0 |
| Sulfonate | 1 | 1 | 1,0 |
| Carbonyl (C=O) | 1 | 1 | 1,0 |
| Carbohydrate | 1 | 1 | 1,0 |
| C-O single bond | 1 | 1 | 1,0 |
| C c single bond | 1 | 1 | 0,9 |
| Hydroxyl (O-H) | 1 | 0 | 0,8 |
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 |
|---|---|---|---|
| PDMS | 844, 873, 1080 | Silicon-oxygen (Si-O), Silicon (Si) | 1 |
| SiO2 | 844, 1739, 699 | Silicon-oxygen (Si-O), Silicon (Si) | 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 844 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
-
C-O single bond confiança 1,0
“In addition, small shoulder peaks at 844 cm-1 (1→4) β and 1077 are related to the glycosidic link and linkages between the sugar cm-1, monomers.”
Biochemical and Structural Characterization of Ferulated Arabinoxylans Extracted from Nixtamalized and Non-Nixtamalized Maize Bran DOI: 10.3390/foods11213374 -
Carbonyl (C=O) confiança 1,0
“The PVA-metal salt complexes can be used as solid electrolytes in different energy conversion A 1733=A ð1Þ RI of carbonyl peak RI ¼ ¼ 844 ½C¼O=CH(cid:1) devices such as batteries/fuel cells, photo-electrochemical A 1578=A RI of terminal dou”
Parveen 等 - 2009 - Synthesis and characterizations of nano-sized Ni(O DOI: 10.1007/s10853-009-3826-8 -
Sulfonate confiança 1,0
“The peaks observed at 3373, 1221, 1037, 1157, 924 and 844 cm-1 can be attributed cm-1 1356-1374 attributed to sulphate (SO 3) group stretching in 1.5-3% CARR:SA (1:0) wafers.”
Akiyode 和 Boateng - 2018 - Composite Biopolymer-Based Wafer Dressings Loaded DOI: 10.3390/polym10080918 -
Oxygen heterocycle confiança 1,0
“In addition, after modification, FTIR peaks that assigned to the epoxy ring (844 cm-1 and 904 cm-1) were decreased.”
Mazlan 和 Abu Hanifah - 2014 - Synthesis and Effect of Modification On Methacylat DOI: 10.1063/1.4895206 -
confiança 1,0
“The (001) interplanar Furthermore, Si-O stretching of Al-Mg-OH (844”
Natkanski 等 - 2013 - Effect of Fe3+ ions present in the structure of po DOI: 10.1007/s10973-013-3225-x -
Ring structure confiança 1,0
“and possibly glycosidic bonds and cyclic structures of On the other hand, the negative cm-1, cm-1 cm-1 influence had peaks at 1152 1109 (C-O stretching and C-C stretching), and 844 (Ring vibration), indicating carbohydrates which might incl”
Spectroscopy and SEM imaging reveal endosymbiont-dependent components changes in germinating kernel through direct and indirect coleorhiza-fungus interactions under stress DOI: 10.1038/s41598-018-36621-8 -
Silicon (Si) confiança 1,0
“structures of PDMS The peaks at 844 and 796 attribute to SiOH-PDMS copolymerization Si-C23, 24.”
Determination of Phenols Isomers in Water by Novel Nanosilica/Polydimethylsiloxane-Coated Stirring Bar Combined with High Performance Liquid Chromatography-Fourier Transform Infrared Spectroscopy DOI: 10.1038/s41598-017-09050-2 -
C c single bond confiança 0,9
“Text: '844 (νCC, rCH)'”
Sodium montmorillonite/ureasil-poly(oxyethylene) nanocomposite as potential adsorbent of cationic dye DOI: 10.1016/j.clay.2017.11.009
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