What absorbs at 891 cm⁻¹ in an FTIR spectrum?
A band near 891 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 891 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 |
| Methoxy (OCH3) | 3 | 3 | 1,0 |
| Methacrylate | 3 | 3 | 1,0 |
| C-O single bond | 3 | 3 | 1,0 |
| Acetate | 3 | 3 | 1,0 |
| Secondary amine | 2 | 2 | 1,0 |
| Metal oxygen | 2 | 2 | 1,0 |
| Alkene (C=C) | 2 | 1 | 1,0 |
| C c single bond | 1 | 1 | 1,0 |
| Carbonate | 1 | 1 | 1,0 |
| Methyl | 1 | 1 | 1,0 |
| Ring structure | 1 | 1 | 1,0 |
| C n single bond | 1 | 1 | 1,0 |
| Amide | 1 | 1 | 1,0 |
| Bromine | 1 | 1 | 1,0 |
| Carbon bromine | 1 | 1 | 1,0 |
| N h | 1 | 1 | 1,0 |
| Hydroxyl (O-H) | 1 | 0 | 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 |
|---|---|---|---|
| ZnO | 891, 1400, 3430 | Alkyl C-H, Methacrylate, C-O single bond | 1 |
| iron oxide | 891, 1130, 1744 | Alkyl C-H, Methoxy (OCH3), Methacrylate | 1 |
| ZnO nanoparticles | 891, 1219, 1726 | Alkyl C-H, Methacrylate, C-O single bond | 1 |
| bacterial cellulose | 891, 1050, 1631 | Alkyl C-H, Methoxy (OCH3), Methacrylate | 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 891 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
-
Metal oxygen confiance 1,0
“inter bridges between corner-sharing WO octahedra 6 cm-1), b (*891 stretching of W-O e-W intra bridges cm-1) (*815 between edge-sharing WO octahedra and 6 cm-1).”
Rao 和 Rajkumar - 2008 - Investigation of 12-tungstophosphoric acid support DOI: 10.1007/s10562-007-9279-2 -
Alkyl C-H confiance 1,0
“The lower band and peak at 891 and 690 represent the C-H of aromatics, N-H of primary and secondary amines, and alkyl halides C-Br stretch, respectively [41].”
Abdelmigid 等 - 2022 - Green Synthesis of Zinc Oxide Nanoparticles Using DOI: 10.3390/molecules27041236 -
Acetate confiance 1,0
“The main cm-1 cm-1 intensity at 1274 is assignable to C-O deformation from the -COOH and the band at 891 is belonging bonds40,41.”
Influence of gamma irradiation on rosin properties and its antimicrobial activity DOI: 10.1038/s41598-023-31372-7 -
confiance 1,0
“cm-1 cm-1, 1605 and 3383-3601 being assigned to the vibrational modes of the deformation IR bands of PTA situated at 523 cm-1, 594 cm-1, 797 cm-1, 891 cm-1, 982 cm-1, 1080 cm-1, 1605 (O corresponds to corner oxygen atoms), W-O e-W stretchin”
The Photoluminescence and Vibrational Properties of Black Phosphorous Sheets Chemically/Electrochemically Functionalized in the Presence of Diphenylamine DOI: 10.3390/polym14214479 -
Amide confiance 1,0
“Independently of the initial C/N ratio in the (r2 (r2 = = 0.73), F1 were found for the bands 891 1151 upper part, the highest negative loading of C/N on F1 and”
Biester 等 - 2014 - Comparison of different methods to determine the d DOI: 10.5194/bg-11-2691-2014 -
confiance 1,0
“suber of before Cu(II) adsorption showed a peak cm-1which corresponds to a C-H deformation at 891 cm-1 in cellulose.”
Mebarki 等 - 2019 - Lignocellulosic fraction of the pericarps of the a DOI: 10.2478/pjct-2019-0028 -
Ring structure confiance 1,0
“The peak intensity positioned while the 891 cm-1 peak belongs to α-glucopyranose ring deformation modes of the C-O cm-1 at 766 is characteristic to a1, 3 of the glycoside unit in dextran [49].”
Preparation and Characterization of Dextran Coated Iron Oxide Nanoparticles Thin Layers DOI: 10.3390/polym13142351 -
Acetate confiance 1,0
“1050 1030 1050 C-O stretching 891 889”
Pre-treatment effect on the structure of bacterial cellulose from Nata de Coco (Acetobacter xylinum) DOI: 10.14314/polimery.2022.3.3
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