What absorbs at 1900 cm⁻¹ in an FTIR spectrum?
A band near 1900 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 1900 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 |
|---|---|---|---|
| Adsorbed carbon monoxide | 4 | 3 | 1,0 |
| Carbonyl (C=O) | 3 | 3 | 1,0 |
| Alkyl C-H | 2 | 2 | 1,0 |
| N-O bond | 2 | 2 | 1,0 |
| Hydroxyl (O-H) | 2 | 2 | 1,0 |
| Amide | 2 | 2 | 1,0 |
| Methacrylate | 2 | 2 | 1,0 |
| Acetate | 2 | 2 | 1,0 |
| Ester | 2 | 2 | 1,0 |
| C-O single bond | 2 | 1 | 1,0 |
| Water (H2O) | 2 | 1 | 1,0 |
| Secondary amine | 1 | 1 | 1,0 |
| C n single bond | 1 | 1 | 1,0 |
| Methyl | 1 | 1 | 1,0 |
| Methoxy (OCH3) | 1 | 1 | 1,0 |
| Ketone | 1 | 1 | 1,0 |
| Carboxyl (COOH) | 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 |
|---|---|---|---|
| biodiesel | 1900, 858, 3470 | Alkyl C-H, Carbonyl (C=O) | 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 1900 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
-
N-O bond confiança 1,0
“Taking into - account the results on CO adsorption and literature data [69-74], 1770cm(cid:2)1 Cr3+(NO) are assigned to the bands at 1900 and”
Influence of dealumination and treatments on the chromium speciation in zeolite CrBEA DOI: 10.1016/j.micromeso.2009.04.038 -
Water (H2O) confiança 1,0
“The most striking feature in the infrared cm(cid:3)1, the oxalic acid dihydrates and the perfluorocarboxylic acid monospectrum of OXAD is the rather strong absorption near 1900 OAH(cid:1)(cid:1)(cid:1)O hydrates in the regions characteristi”
Infrared spectra of hydrogen bond network in lamellar perfluorocarboxylic acid monohydrates DOI: 10.1016/j.saa.2021.119551 -
Adsorbed carbon monoxide confiança 1,0
“However, assignment to ketene cannot and Possible Photoproducts be unequivocal in this spectral region, since carbon monoxide frequencies.27 also absorbs at the same cm-1 The absorptions above 1900 are characteristic of”
Jarmelo 等 - 2008 - Matrix-Isolated Diglycolic Anhydride Vibrational DOI: 10.1021/jp805603b -
confiança 1,0
“The band at about 1900 can be assigned to three-coordinated CO on Pd(111) or bridged CO on (100) planes.”
Facile Redox Synthesis of Novel Bimetallic Crn+/Pd0 Nanoparticles Supported on SiO2 and TiO2 for Catalytic Selective Hydrogenation with Molecular Hydrogen DOI: 10.3390/catal11050583 -
Ester confiança 1,0
“coefficients.42 cm-1) and discuss the loadings or regression Citing (two points: 1900 and 1560 and the area under the Bro:43 cm-1) Kjeldahl and "…we looked at a number of commonly ester C=O stretching band (1900-1728 was calculated occurrin”
Kollar 等 - 2017 - Nuclear Magnetic Resonance (1.40 T) and Mid Infrar DOI: 10.21577/0103-5053.20170031 -
Acetate confiança 1,0
“In the region 1402-1457 bands due to in which the bands due to the formation of imines in the area carbohydrates, glycoproteins, lipids and their characteristic cm-1, between 1900 and 1600 and the bands related to the C-O-H in-plane bending”
Mura 等 - 2012 - FTIR nanobiosensors for Escherichia coli detection DOI: 10.3762/bjnano.3.55 -
Hydroxyl (O-H) confiança 1,0
“t absorption bands below 1900 The signals do match reasonably well with a mixture of h o CO-loss isomers from the parent 1-1 isomer shown in Figure 10b.”
Photodynamics of [FeFe]-Hydrogenase Model Compounds with Bidentate Heterocyclic Ligands DOI: 10.1021/acs.jpcb.9b04675. -
Adsorbed carbon monoxide confiança 1,0
“cm-1 Figure 3A shows that the absorption bands exist at 1750 - 1850 and 1900 cm-1, - 2100 which may be ascribed to bridge type and linear type of CO adsorbed on”
In situ FTIR study on the formation and adsorption of CO on alumina-supported noble metal catalysts from H2 and CO2 in the presence of water vapor at high pressures DOI: 10.1039/c2cp23590k
Tem um espectro com esta banda?
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