What absorbs at 657 cm⁻¹ in an FTIR spectrum?
A band near 657 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 657 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 |
|---|---|---|---|
| Metal oxygen | 3 | 3 | 1,0 |
| Ring structure | 2 | 2 | 1,0 |
| Secondary amine | 1 | 1 | 1,0 |
| C n single bond | 1 | 1 | 1,0 |
| Amide | 1 | 1 | 1,0 |
| Nitrogen heterocycle | 1 | 1 | 1,0 |
| Alkene (C=C) | 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 |
|---|---|---|---|
| TiO2 | 657, 1700, 1093 | Metal oxygen | 1 |
| TiO | 657, 1730, 1699 | Metal oxygen | 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 657 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
-
confiance 1,0
“The Raman peaks observed at 483 are attributed to the stretching mode vibration of Mn-O bonds, and another peak observed at cm-1 657 corresponds to A1g mode vibration of Mn 3O 4.”
Synthesis and characterization of Mn3O4/MnSnO3 nanocomposites for supercapacitor applications DOI: 10.1007/s12588-019-09250-7 -
Alkene (C=C) confiance 1,0
“The FTIR spectrum showed peaks at 1,592, 1,627 and 1,657 cm-1 assigned to C=C stretching of the imidazole ring and characteristic peaks at 1,605 and 1,766 assigned to C=O stretching.”
Synthesis, Characterization and Reactivity Ratio Study of Poly(di(tri-n-butyltin) citraconate-co-N-vinylimidazole) DOI: 10.3390/molecules15074750 -
confiance 1,0
“For this same 31, 39, and 46), thus exposing underneath layers, corresamples (showing a gypsum rich content) strong peaks late with the FTIR analysis of the samples, which indiascribed to lead white as well as a sharp peaks around cm-1 cate”
Cortea 等 - 2020 - Uncovering hidden jewels an investigation of the DOI: 10.1186/s40494-020-00401-3 -
Ring structure confiance 1,0
“The peaks cm-1 cm-1 occurring at 657 and 554 can be associated with the out of plane vibrations of ring structure and C-”
Okeke 等 - 2018 - Characterization of hibiscus sabdariffa fiber as p DOI: 10.1590/S1517-707620180004.0550 -
confiance 1,0
“Previous researchers have demonstrated that the peak around 657 is attributed 2 cm-1 to Ti-O-Ti stretching vibration, whereas the peak around 590 is due to the vibration of Ti-O-O.”
Physicochemical and Rheological Properties of a Transparent Asphalt Binder Modified with Nano-TiO2 DOI: 10.3390/nano10112152 -
Amide confiance 1,0
“cm-1 Other bands at 657.1 and 611.8 indicated an O=C-N bend of aliphatic secondary cm-1 amides [38].”
Adsorptive Performance of Walnut Shells Modified with Urea and Surfactant for Cationic Dye Removal DOI: 10.3390/w15081536 -
confiance 1,0
“In addition, the intense bands seen at 756 657 cm-1 and 489 ascribed to the Ti-O stretching vibration and confirmed the existence of TiO nanoparticles.”
UV-shielding properties of a cost-effective hybrid PMMA-based thin film coatings using TiO2 and ZnO nanoparticles: a comprehensive evaluation DOI: 10.1038/s41598-023-34120-z -
confiance 0,8
“Characteristic apatite signal”
Mirkovic 等 - 2018 - Structural, Morphological and Electrical Propertie DOI: 10.2298/SOS1801095M
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