What absorbs at 1775 cm⁻¹ in an FTIR spectrum?
A band near 1775 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 1775 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 |
|---|---|---|---|
| Carbonyl (C=O) | 6 | 5 | 1,0 |
| Methacrylate | 5 | 5 | 1,0 |
| Carboxyl (COOH) | 5 | 5 | 1,0 |
| Acetate | 5 | 5 | 1,0 |
| Ketone | 4 | 4 | 1,0 |
| Ester | 4 | 4 | 1,0 |
| Amide | 4 | 4 | 1,0 |
| Alkyl C-H | 2 | 2 | 1,0 |
| Methoxy (OCH3) | 2 | 2 | 1,0 |
| C-O single bond | 2 | 2 | 1,0 |
| Carbohydrate | 2 | 2 | 1,0 |
| Ring structure | 1 | 1 | 1,0 |
| Imide | 1 | 1 | 1,0 |
| Metal oxygen | 1 | 1 | 1,0 |
| Alkene (C=C) | 1 | 1 | 1,0 |
| Hydroxyl (O-H) | 1 | 1 | 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 |
|---|---|---|---|
| PVA | 1775, 1660, 2930 | Acetate, Methacrylate, Carbonyl (C=O) | 2 |
| cellulose nanocrystals | 1775, 1110, 1640 | Acetate, Methacrylate, Carbonyl (C=O) | 1 |
| magnetite | 1775, 1740, 1263 | Carboxyl (COOH), Methacrylate, Acetate | 1 |
| honey | 1775, 2005, 1199 | Methacrylate, Acetate | 1 |
| GO | 1775, 1720, 1182 | Methacrylate, Acetate, Carboxyl (COOH) | 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 1775 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
-
Carboxyl (COOH) confiança 1,0
“Spectrum FTIR Carboxymethyl kappa-carrageenan Based on the FTIR spectrum, it appears that some of the hydroxyl groups have been replaced with carboxyl cm-1 cm-1 and 1417 confirming groups, indicated by the appearance of absorption peaks at”
The capability of nanomagnetite carboxymethyl kappa-carrageenan coated to adsorp metal ions DOI: 10.1063/5.0000680 -
Acetate confiança 1,0
“The absence of the vibration band located around 1775 is attributed to the elongated vibrations of the specific C=O bond of the hemicellulose residues”
Part A: Biodegradable Bio-Composite Film Reinforced with Cellulose Nanocrystals from Chaetomorpha linum into Thermoplastic Starch Matrices DOI: 10.3390/polym15061542 -
Carbohydrate confiança 1,0
“Sci.2022,12,9645 5of9 and 1775 cm-1 which are attributed to the carbohydrates and O-H stretching vibrations”
Botanical Origin Assessment of Honey Based on ATR-IR Spectroscopy: A Comparison between the Efficiency of Supervised Statistical Methods and Artificial Intelligence DOI: 10.3390/app12199645 -
Hydroxyl (O-H) confiança 1,0
“cm-1, cm-1, O-H, C=O, C=C, -CH 2, C-O stretching, and C-H bending at 3741.18 1774.84 cm-1, cm-1, cm-1, cm-1, 1689.04 1511.76 1182.03 and 882.79 respectively.”
Evaluation of Structural and Optical Properties of Graphene Oxide-Polyvinyl Alcohol Thin Film and Its Potential for Pesticide Detection Using an Optical Method DOI: 10.3390/photonics9050300 -
Acetate confiança 1,0
“1153cm(cid:3)1 which the carbonyl stretching vibration of six-membered cyclic (C-O stretching of ester) and (C-N stretching of aliphatic ester).17,18 1760cm(cid:3)1, anhydrides exhibited unique peaks at 1800 and amine and/or C-O stretching”
DSC-FTIR microspectroscopy used to investigate the heat-induced intramolecular cyclic anhydride formation between Eudragit E and PVA copolymer DOI: 10.1038/pj.2011.15; -
Acetate confiança 1,0
“The absorption bands observed at 1775 cm-1 and 1716 were attributed to the asymmetric and symmetric stretching of C=O in the imide ring, Polymers2017,9,734”
Preparation and Evaluation of a Polyimide-Coated Ultrafine Gilt Molybdenum Wire and Its Knitted Mesh Used for Electromagnetic Reflectors DOI: 10.3390/polym9120734 -
Alkyl C-H confiança 1,0
“In the Figure 4 (A) the shows crystalline and 2850 (CH stretching), 1775 (C=O stretchIndian Journal of Pharmaceutical Education and Research | Vol 52 | Issue 4 [Suppl] | Oct-Dec, 2018”
Udapurkar 等 - 2018 - Diosmin Phytosomes Development, Optimization and DOI: 10.5530/ijper.52.4s.73 -
confiança 0,8
“Attributed to specific vibration of thiophene.”
Surface Characterization of Modified Electrodes Based on 4-(Azulen-1-yl)-2,6-bis((E)-2-(thiophen-2-yl)vinyl)pyridine DOI: 10.3390/sym14122506
Tem um espectro com esta banda?
Carregue seu espectro FTIR e obtenha um relatório de interpretação completo — atribuições de picos com citações da literatura, correspondências de biblioteca e uma cadeia de evidências com nível de confiança — em segundos.