What absorbs at 2971 cm⁻¹ in an FTIR spectrum?
A band near 2971 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 2971 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 |
|---|---|---|---|
| Alkyl C-H | 6 | 6 | 1,0 |
| Hydroxyl (O-H) | 3 | 3 | 1,0 |
| Methyl | 2 | 2 | 1,0 |
| Methoxy (OCH3) | 2 | 2 | 1,0 |
| Secondary amine | 1 | 1 | 1,0 |
| N h | 1 | 1 | 1,0 |
| Methacrylate | 1 | 1 | 1,0 |
| C-O single bond | 1 | 1 | 1,0 |
| Acetate | 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 |
|---|---|---|---|
| hydrogel | 2971, 1632, 1062 | Alkyl C-H, Hydroxyl (O-H) | 2 |
| AgNPs | 2971, 1232, 1048 | Alkyl C-H, Hydroxyl (O-H), Methoxy (OCH3) | 1 |
| TiO2 | 2971, 1700, 1093 | Hydroxyl (O-H), Alkyl C-H, Methoxy (OCH3) | 1 |
| iron oxide | 2971, 1130, 891 | Alkyl C-H, Methoxy (OCH3), Hydroxyl (O-H) | 1 |
| TiO2 nanoparticles | 2971, 1700, 455 | Hydroxyl (O-H), Alkyl C-H, Methoxy (OCH3) | 1 |
| iron oxide nanoparticles | 2971, 2972, 528 | Hydroxyl (O-H), Alkyl C-H, 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 2971 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
-
Hydroxyl (O-H) confiança 1,0
“cm-1, 1364, 1218 and 1088 The broadband, at 3455 is due to the O-H group stretching cm-1 vibration .Significant peaks were found at (2971, 2947) ascribed to methyl group, The”
Green Synthesis of Iron Oxide Nanoparticles by Aqueous Leaves Extract of Mentha Pulegium .L: Effect of Ferric Chloride Concentration on The Type of Product DOI: 10.1016/j.matlet.2020.127364 -
Acetate confiança 1,0
“2970.83 and strong C-O stretch (1092.93 & 1113.28 XRD peaks showed that synthesized TiO nanoparticles 2 have both anatase and rutile phase.”
Biosynthesis of TiO2 nanoparticles by Acalypha indica; photocatalytic degradation of methylene blue DOI: 10.1007/s13204-021-01761-3 -
Alkyl C-H confiança 1,0
“LLM confirmed rule peak-group candidate”
A Comprehensive Approach to Derivatization: Elemental Composition, Biochemical, and In Silico Studies of Metformin Derivatives Containing Copper and Zinc Complexes DOI: 10.3390/molecules28031406 -
N h confiança 1,0
“The NH stretching was assigned at 2971 The peaks of 1172 and 3 1 1 cm-1 2631cm-1.”
Mohammed 等 - 2020 - Synthesis and Physico-Chemical Characterization of DOI: 10.1063/1.5142126 -
Alkyl C-H confiança 1,0
“3, the with phenolic compounds such as 2, 6-dimethoxy-phenol, 2cm-1 adsorption at 2970.96 indicates the C-H stretching of the methoxy-4-(1-propenyl)-(E)-phenol and 3,4,5trimethoxy-phenol alkyl group in AgNPs [9].”
Biomimetic synthesis and anticancer activity of <i>Eurycoma longifolia</i> branch extract‐mediated silver nanoparticles DOI: 10.1049/iet-nbt.2016.0181 -
Alkyl C-H confiança 1,0
“This study provides valuable information C-H for structurally designing and developing potent coumarin stretching), 2971, 2929 & 2838 (aliphatic stretching), 1729 (C]O d-lactone”
Coumarin–carbazole based functionalized pyrazolines: synthesis, characterization, anticancer investigation and molecular docking DOI: 10.1039/d1ra03970a -
Alkyl C-H confiança 1,0
“Asymmetric valence vibrations of CH ence vibrations of C-H bond from methyl groups have group 2 cm-1, given the bands with maxima at 2971 and 2876 have produced the absorption band with maximum at”
{The evaluation of temperature and ph influences on equilibrium swelling of poly(n-isopropylacrylamide-co-acrylic acid) hydrogels} DOI: 10.2298/HEMIND161018001Z -
Alkyl C-H confiança 0,9
“Explicit: 'bands between 2856 and 2971 were assigned to the C-H symmetric and asymmetric stretching'”
Yao 等 - 2023 - Facile Preparation and Adsorption Behavior Studies DOI: 10.21203/rs.3.rs-1889584/v1
Tem um espectro com esta banda?
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