What absorbs at 2903 cm⁻¹ in an FTIR spectrum?
A band near 2903 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 2903 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 | 4 | 4 | 1,0 |
| N h | 2 | 2 | 1,0 |
| Secondary amine | 1 | 1 | 1,0 |
| Amine primary | 1 | 1 | 1,0 |
| Siloxane (Si-O-Si) | 1 | 1 | 1,0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1,0 |
| Fatty acid | 1 | 1 | 1,0 |
| Ring 6m | 1 | 1 | 1,0 |
| Carbohydrate | 1 | 1 | 0,8 |
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 |
|---|---|---|---|
| alginate | 2903, 1100, 1715 | Alkyl C-H | 1 |
| cellulose | 2903, 1735, 1650 | Alkyl C-H | 1 |
| hemicellulose | 2903, 1730, 897 | Alkyl C-H | 1 |
| GO | 2903, 1720, 1182 | Alkyl C-H | 1 |
| collagen | 2903, 1408, 1660 | Alkyl C-H, N h | 1 |
| sodium alginate | 2903, 1636, 1080 | 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 2903 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
“Figure 1a reveals a broad and intense band in the region of 3321 cm-1 stretching vibrations of cellulose, hemicellulose, and lignin [14, 15] while a peak at 2903 corresponded cm-1 to the -CH stretching vibrations.”
Nanocellulose-silica polyethersulfone hybrid composite stabilized lipase for esterification DOI: 10.1063/1.5125521 -
Alkyl C-H confiance 1,0
“LLM confirmed rule peak-group candidate”
Characteristics and Preparation of Designed Alginate-Based Composite Scaffold Membranes with Decellularized Fibrous Micro-Scaffold Structures from Porcine Skin DOI: 10.3390/polym13203464 -
Alkyl C-H confiance 1,0
“phospholipids cm-1 The 2903 and 2861 bands represented the CH symmetric stretch, and”
Lazaro-Pacheco 等 - 2022 - Deciphering the structural and chemical compositio DOI: 10.1080/05704928.2020.1843471 -
confiance 1,0
“The changes in Si-O-Si bonds The two peaks at 2903 and 2829 corresponding cm-1 cm-1 occurring in between 1100 -1000 were due to the to asymmetrical and symmetrical stretching of CH and 3”
Loganathan 和 Chandrasekar - 2013 - Analysis of Surface Tracking of Micro and Nano Siz DOI: 10.5370/JEET.2013.8.2.345 -
Amine primary confiance 1,0
“cm-1 the peaks 2903 and 2851 Primary amine, NH bend group is responsible for the peaks 1614 and 1524 The 1232 peak is produced by cm-1.”
Manjunatha 等 - 2023 - Eco-friendly synthesized silver nanoparticles from DOI: 10.21203/rs.3.rs-2345744/v1 -
Alkyl C-H confiance 1,0
“LLM confirmed rule peak-group candidate”
Adapalene-loaded poly(#_#x03B5;-caprolactone) microparticles: Physicochemical characterization and in vitro penetration by photoacoustic spectroscopy DOI: 10.1371/journal. -
confiance 1,0
“1472 sity due to formation of the reduced dimers which contain the same cm-1is The band at 2903 attributed to the N-H stretching of groups.”
Spectroelectrochemical studies of poly(N-methylaniline) formation, redox behaviour and degradation. A comparison with polyaniline DOI: 10.1016/j.electacta.2013.10.179 -
Carbohydrate confiance 0,8
“Hydrogen bond stretching of CH and CH of cellulose.”
Enhanced arsenic (iii) adsorption from aqueous solution by magnetic pine cone biomass DOI: 10.1016/j.matchemphys.2018.09.067
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