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
Réponse rapide
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.
Attributions possibles de groupes fonctionnels
| Groupe fonctionnel | Faits à l＇appui | Sources citées | Confiance maximale |
|---|---|---|---|
| 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 |
Le classement reflète les preuves bibliographiques accumulées, et non une règle faisant autorité. Confirmez toujours dans le contexte de votre échantillon.
Matériaux possibles
| Matériel | Pics de support | Groupes chevauchants | Sources citées |
|---|---|---|---|
| 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 |
Les matériaux sont affichés uniquement lorsque le même ensemble de littérature soutient cette bande et au moins un pic caractéristique supplémentaire.
Logique du spectre
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.
Utilisation réelle
Ce type de requête est courant dans l＇identification des polymères, le criblage des plastiques inconnus, le dépannage du contrôle qualité, la vérification des matériaux recyclés et l＇examen de l＇attribution des pics appuyée par la littérature.
Erreurs courantes
- Traiter une bande isolée comme preuve d＇un matériau sans vérifier au moins un ou deux pics de support.
- Ignorer le chevauchement : plusieurs groupes fonctionnels peuvent contribuer près du même nombre d＇onde.
- Sauter la validation lorsque des additifs, des mélanges, l＇oxydation ou la contamination peuvent déformer le spectre.
Conseil de vérification
Lorsque l＇ambiguïté persiste, validez l＇hypothèse avec DSC, GC-MS ou TGA, en particulier pour les mélanges, les échantillons dégradés et les polymères chargés.
Bibliographie derrière ces attributions
-
Hydroxyl (O-H) confiance 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 confiance 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 confiance 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 confiance 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 confiance 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 confiance 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 confiance 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 confiance 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
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