What absorbs at 2977 cm⁻¹ in an FTIR spectrum?
A band near 2977 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 2977 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 | 10 | 10 | 1,0 |
| Ring structure | 1 | 1 | 1,0 |
| Carbohydrate | 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 |
|---|---|---|---|
| cellulose | 2977, 1735, 1650 | Alkyl C-H, Carbohydrate | 1 |
| hemicellulose | 2977, 1730, 897 | Alkyl C-H | 1 |
| lignin | 2977, 1035, 1510 | Alkyl C-H | 1 |
| biomass | 2977, 1082, 1282 | Alkyl C-H | 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 2977 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
“cm-1 The peaks that appear at 2977 and 2898 were 3.3 FTIR-ATR spectroscopy characterization associated with the stretching of the C-H bond.”
Mondragon-Cortez 等 - 2022 - Application of Fourier transform infrared spectros DOI: 10.24275/rmiq/Alim2806 -
Alkyl C-H confiance 1,0
“These waveband peak results 2977 is attributed to the C-H vibrations of the may indicate a reduction in sugar, which would and -CH moiety vibrations in alkyl group and -CH 2”
Use of thermal imaging and Fourier transform infrared spectroscopy for the pre-symptomatic detection of cucumber downy mildew DOI: 10.1007/s10658-019-01775-2 -
Alkyl C-H confiance 1,0
“LLM confirmed rule peak-group candidate”
Ajibade 和 Mbese - 2014 - Synthesis and Characterization of Metal Sulfides N DOI: 10.1155/2014/752394 -
Alkyl C-H confiance 1,0
“Bond (vibration) Degradation product 2977 C-H (asymmetric stretching) C xH y”
Hejna 等 - 2017 - Performance properties of rigid polyurethane-polyi DOI: 10.1515/epoly-2017-0012 -
Alkyl C-H confiance 1,0
“at 2977 and 2924 cm-1 due to stretching vibration of C-H (the bands at 2994, 2977, 2924, 2904 and 2890 would be due to”
Oliveira 等 - 2016 - FTIR analysis and quantification of phenols and fl DOI: 10.1590/S1517-707620160003.0072 -
Alkyl C-H confiance 1,0
“peaks at 2977 and 2931 were cm-1 assigned to C-H stretching vibration within the ring;”
In Vitro Interaction of Doxorubicin-Loaded Silk Sericin Nanocarriers with MCF-7 Breast Cancer Cells Leads to DNA Damage DOI: 10.3390/polym13132047 -
Alkyl C-H confiance 1,0
“The absorptions at 2977 and 2929, cm-1 2900 are allocated to symmetric and anti-symmetric vibration of CH in the alkyl chain in EO, tween 20, 2”
Nanoliposomes containing three essential oils from the Artemisia genus as effective larvicides against Aedes aegypti and Anopheles stephensi DOI: 10.1038/s41598-023-38284-6 -
Alkyl C-H confiance 1,0
“1026 C-O stretching 2977 C-H stretching 2875 C-H stretching”
Zhuang 等 - 2020 - Observation of Potential Contaminants in Processed DOI: 10.3390/app10124345
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