What absorbs at 2983 cm⁻¹ in an FTIR spectrum?
A band near 2983 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 5 cited sources
Réponse rapide
A band near 2983 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 | 5 | 4 | 1,0 |
| Secondary amine | 1 | 1 | 1,0 |
| C n single bond | 1 | 1 | 1,0 |
| C-O single bond | 1 | 1 | 1,0 |
| Ketone | 1 | 1 | 1,0 |
| Ester | 1 | 1 | 1,0 |
| Carboxyl (COOH) | 1 | 1 | 1,0 |
| Carbonyl (C=O) | 1 | 1 | 1,0 |
| Amide | 1 | 1 | 1,0 |
| Methyl | 1 | 1 | 1,0 |
| Methoxy (OCH3) | 1 | 1 | 1,0 |
| Methacrylate | 1 | 1 | 1,0 |
| Acetate | 1 | 1 | 1,0 |
| N h | 1 | 1 | 1,0 |
| Aromatic ring | 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 |
|---|---|---|---|
| PVP | 2983, 1648, 3414 | Alkyl C-H, Secondary amine | 1 |
| chitosan | 2983, 1650, 1655 | Alkyl C-H, C-O single bond | 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 2983 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
-
Alkyl C-H confiance 1,0
“asymmetric C-H stretch in CH at 2983 symmetric "umbrella" bend at 1377 3”
Incorporation of Natural Blueberry, Red Grapes and Parsley Extract By-Products into the Production of Chitosan Edible Films DOI: 10.3390/polym13193388 -
Alkyl C-H confiance 1,0
“cm-1 changes at each step of electrode modification could be Peaks at 2983 and 1238 correspond to C-H and 2observed clearly from the FE-SEM images.”
AuNPs/CNF-modified DNA biosensor for early and quick detection of O. tsutsugamushi in patients suffering from scrub typhus DOI: 10.1007/s13205-020-02432-w -
Aromatic ring confiance 1,0
“f cm-1 reaction (Table 2, entry 2) was performed without a solvent, -C-H FTIR: 3081.43 for aromatic stretching, 2983.48 cm-1 without cashew shell extract, and with microwave irradiation -C-H for aliphatic stretching, 1654.06 and 1621.27”
Manjare 等 - 2023 - Microwave-Assisted Rapid and Green Synthesis of Sc DOI: 10.1021/acsomega.2c05187 -
confiance 1,0
“N-H broad bend at 3054 and 2983 cm-1 The peak at 1058 was shifted to lower wave-numbers As revealed in the XRD pattern of theophylline in Figure”
Development of Theophylline Microbeads Using PregelatinizedBreadfruit Starch (Artocarpus altilis) as a Novel Co-polymer for Controlled Release DOI: 10.15171/apb.2019.012 -
Alkyl C-H confiance 1,0
“Eudragit® spectra of DTPA penta-ethyl ester and RL PO have absorptions at 2983, 1732, a n cm-1, 1190 and 1029 which correspond to sp3 CH and CH 3, C=O, C-O and C-N stretching u 2 s cm-1 c vibrations, respectively.”
Yang 等 - 2014 - Solid dispersions of the penta-ethyl ester prodrug DOI: 10.3109/10837450.2013.836216.
Avez-vous un spectre avec cette bande ?
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