What absorbs at 931 cm⁻¹ in an FTIR spectrum?
A band near 931 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 931 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 |
|---|---|---|---|
| Methoxy (OCH3) | 4 | 4 | 1,0 |
| Methacrylate | 4 | 4 | 1,0 |
| C-O single bond | 4 | 4 | 1,0 |
| Acetate | 4 | 4 | 1,0 |
| Phosphate (PO4) | 2 | 2 | 1,0 |
| N h | 1 | 1 | 1,0 |
| Water (H2O) | 1 | 1 | 1,0 |
| Secondary amine | 1 | 1 | 1,0 |
| C n single bond | 1 | 1 | 1,0 |
| Amide | 1 | 1 | 1,0 |
| Ammonium | 1 | 1 | 1,0 |
| Carbonate | 1 | 1 | 0,9 |
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 |
|---|---|---|---|
| sodium alginate | 931, 1636, 1080 | Methacrylate, C-O single bond, Acetate | 1 |
| curcumin | 931, 1063, 1153 | Methacrylate, Acetate, 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 931 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
-
Phosphate (PO4) confiance 1,0
“Same as 902 cm-1”
Effects of titanium nanoparticles on self-cleaning and structural features of zinc-magnesium-phosphate glass DOI: 10.1016/j.materresbull.2015.11.022 -
Phosphate (PO4) confiance 1,0
“LLM confirmed rule peak-group candidate”
Ascolani Yael 等 - 2014 - Abiotic Degradation of Glyphosate into Aminomethyl DOI: 10.1021/jf502979d -
Ammonium confiance 1,0
“of neat APP is associated with the appearance of the two intense peaks of ammonia at 966 and 931 decomposition of neat APP is associated with the appearance of the two intense peaks of ammonia In Figure 7, the intensities of these typical w”
Development of Bioepoxy Resin Microencapsulated Ammonium-Polyphosphate for Flame Retardancy of Polylactic Acid DOI: 10.3390/molecules24224123 -
Acetate confiance 1,0
“cm-1 agar-specific The band at 931 corresponds to the C-O-O group present in the 3,6 -anhydrogalactose, and cm-1 the bands between 820 and 860 indicate the presence groups[53-57].”
Lima de Castro 等 - 2018 - Polysaccharides of red alga Gracilaria intermedia DOI: 10.1590/0104-1428.013116 -
Acetate confiance 1,0
“3 ScientiFic REpoRTs | 7: | DOI:10.1038/s41598-017-13725-1 13254 www.nature.com/scientificreports/ (cm-1) Frequency Assignment Symmetric C-O stretching from ~931 carbohydrates”
Estimation of the age of human bloodstains under the simulated indoor and outdoor crime scene conditions by ATR-FTIR spectroscopy DOI: 10.1038/s41598-017-13725-1 -
Amide confiance 1,0
“DNAandRNAribose stretching DNAandRNAribose-phosphatechain C-N+-Cstretching 931 vibrationofRNA DNAandRNAribose-phosphatechain C-N+-Cstretching 914”
Fourier-Transform Infrared Spectroscopy as a Discriminatory Tool for Myotonic Dystrophy Type 1 Metabolism: A Pilot Study DOI: 10.3390/ijerph18073800 -
Water (H2O) confiance 1,0
“OeH and that are assigned to stretching vibrations of SieOHandAleAleOH,apeakat3371cm(cid:3)1correspondstoHeOeH 1627cm(cid:3)1 stretching vibrations of interlayer water, a peak at corHeOeH responds to bending mode of adsorbed water, peaks at”
Curcumin encapsulated dual cross linked sodium alginate/montmorillonite polymeric composite beads for controlled drug delivery DOI: 10.1016/j.jpha.2020.07.002 -
Acetate confiance 1,0
“and the stretching vibration of the C-O-C appeared at 930.62 cm-1.”
Synthesis of Phosphated K-Carrageenan and Its Application for Flame-Retardant Waterborne Epoxy DOI: 10.3390/polym10111268
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