What absorbs at 1251 cm⁻¹ in an FTIR spectrum?
A band near 1251 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 1251 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 | 6 | 6 | 1,0 |
| Acetate | 6 | 6 | 1,0 |
| Methoxy (OCH3) | 5 | 5 | 1,0 |
| C-O single bond | 5 | 5 | 1,0 |
| Amide | 3 | 2 | 1,0 |
| Alkyl C-H | 2 | 2 | 1,0 |
| Aromatic ring | 2 | 2 | 1,0 |
| Carbonyl (C=O) | 2 | 2 | 1,0 |
| Carboxyl (COOH) | 2 | 2 | 1,0 |
| Ring structure | 2 | 2 | 1,0 |
| Ester | 2 | 2 | 1,0 |
| Phosphate (PO4) | 2 | 1 | 1,0 |
| C c single bond | 1 | 1 | 1,0 |
| Ketone | 1 | 1 | 1,0 |
| Oxygen heterocycle | 1 | 1 | 1,0 |
| Borate | 1 | 1 | 1,0 |
| N h | 1 | 1 | 1,0 |
| Carbohydrate | 1 | 1 | 0,8 |
| Phosphorus | 1 | 0 | 1,0 |
| Nitrogen heterocycle | 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 |
|---|---|---|---|
| PVA | 1251, 1660, 2930 | Acetate, Methacrylate, C-O single bond | 1 |
| Fe3O4 | 1251, 2358, 1673 | Methacrylate, Acetate | 1 |
| ZnS | 1251, 1650, 1116 | Acetate, Methacrylate | 1 |
| Fe3O4 nanoparticles | 1251, 1673, 1470 | 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 1251 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
“The moderate cm-1 belongs to N-H stretching absorption peak at 1251”
In-doped ZnS nanoparticles: structural, morphological, optical and antibacterial properties DOI: 10.1007/s00339-021-04425-9 -
Borate confiança 1,0
“cm-1 *1251 The band centered at is attributed to B-O The resulted IR data were used in this research in order to stretching vibrations in [BO 3] units from boroxol cm-1”
Rada 等 - 2009 - Structural and electronic properties of tellurite DOI: 10.1007/s10853-009-3433-8 -
Acetate confiança 1,0
“cm-1 C-O stretching 1251 cm-1”
Influence of Polyvinyl Alcohol (PVA) on PVA-Poly-N-hydroxyethyl-aspartamide (PVA-PHEA) Microcrystalline Solid Dispersion Films DOI: 10.1208/s12249-020-01811-z -
Oxygen heterocycle confiança 1,0
“For spectrum, the main peaks located at 1251 and 877 LENR cm-1 are assigned for symmetric and asymmetric stretching of epoxide ring, respectively.”
Azhar 等 - 2017 - Epoxidation and Hydroxylation of Liquid Natural Ru DOI: 10.17576/jsm-2017-4603-17 -
Amide confiança 1,0
“resents another alternative by accurately quantifying ligand The maximum amide peaking at 1653, 1546 and 1251 cm-1 density, but such techniques require matrix digestion [50].”
Boulet-Audet 等 - 2015 - Cleaning-in-place of immunoaffinity resins monitor DOI: 10.1007/s00216-015-8871-3) -
Acetate confiança 1,0
“the C-O-C peaks of the ester bond at 1251 and cm-1 1024 also confirm this.”
Synthesis and Application of Tackifying Dispersant Poly (Vinyl Alcohol-Acrylic Acid-Triallyl Cyanate) DOI: 10.3390/polym14030557 -
Phosphate (PO4) confiança 1,0
“Furthermore, an cm-1) ester bond in the FTIR spectra (C=O stretching at 1745 was selected for the estimation cm-1) of lipids and a phosphate functional group bond (P=O stretching at 1251 was selected for the estimation of polyphosphates.”
Calcium Affects Polyphosphate and Lipid Accumulation in Mucoromycota Fungi DOI: 10.3390/jof7040300 -
Acetate confiança 1,0
“(b) (c) and The main vibrations, where the greatest changes in the wood occurred, were identified at the peaks at 1251 cm-1, which is related to the C-O stretching vibration;”
Moya 等 - 2022 - In Situ Synthesis of Fe3O4 Nanoparticles and Wood DOI: 10.3390/ma15093394
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