What absorbs at 869 cm⁻¹ in an FTIR spectrum?
A band near 869 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 7 cited sources
Réponse rapide
A band near 869 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 | 2 | 2 | 1,0 |
| Methoxy (OCH3) | 1 | 1 | 1,0 |
| Methacrylate | 1 | 1 | 1,0 |
| C-O single bond | 1 | 1 | 1,0 |
| Acetate | 1 | 1 | 1,0 |
| Hydroxyl (O-H) | 1 | 1 | 1,0 |
| Aromatic ring | 1 | 1 | 1,0 |
| Silicon (Si) | 1 | 1 | 1,0 |
| Siloxane (Si-O-Si) | 1 | 1 | 1,0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1,0 |
| Metal oxygen | 1 | 1 | 1,0 |
| Carbonate | 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 |
|---|---|---|---|
| HCl | 869, 1708, 1032 | Methacrylate, C-O single bond, Methoxy (OCH3) | 1 |
| polycaprolactone | 869, 1580, 1751 | Methacrylate, Methoxy (OCH3), C-O single bond | 1 |
| PLA | 869, 1650, 1073 | Alkyl C-H, Methacrylate, Methoxy (OCH3) | 1 |
| PCL | 869, 1751, 1724 | Alkyl C-H, Methacrylate, Methoxy (OCH3) | 1 |
| biomass | 869, 1082, 1282 | Alkyl C-H, Methacrylate, C-O single bond | 1 |
| PAni | 869, 2930, 1300 | 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 869 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
“869cm-1 films C-H and at in PAni doped may be due to out of plane cm-1 film bending.”
Influence of polyaniline doping concentration in (Bi0.5Sb0.5)2S3 thin polycrystalline films on structural, electrical and optical properties DOI: 10.1016/j.jnoncrysol.2010.03.012 -
Metal oxygen confiance 1,0
“Another peak at cm-1 869 in the BFD spectrum, can occur from the Al-O stretching in AlO4 tetrahedra of aluminate, or from symmetric Si-O-Si stretching in SiO4 tetrahedra of alite (Ghosh and Handoo, 1980;”
Micro-characterization of Dust and Materials of Dust Origin at a Cement Industry Located in Bangladesh DOI: 10.4209/aaqr.220109 -
Aromatic ring confiance 1,0
“The presence of both bands together with the band at 869 due to the aromatic C-H out-of-plane bending vibrations, confirms the presence of a significant amount of hydrolysable tannins in the eucalyptus bark extract.”
Santos 等 - 2023 - Forest by-Product Valorization Pilot-Scale Pinus DOI: 10.3390/f14050895 -
Hydroxyl (O-H) confiance 1,0
“literatures10,17 cm-1 According to peak at 1065 is assigned to BRB-PMo hybrid was synthesized by addition of 0.05 12 cm-1 inner P-O a-Mo bond, peak at 790 to Mo-O d-Mo bridges, g/mL aqueous solution of butylrhodamine B dropwise to a cm-1 cm”
Zeng 等 - 2013 - Electrochemical and Fluorescent Investigation of I DOI: 10.14233/ajchem.2013.14039 -
Acetate confiance 1,0
“The following bands belong to PCL: C=O stretching (1724, 1182 valence cm-1), cm-1) C-O-C vibrations (869, 1043, and 1109 C=C stretching (1286 [28,33].”
Polymer Composite Materials Based on Polylactide with a Shape Memory Effect for “Self-Fitting” Bone Implants DOI: 10.3390/polym13142367 -
confiance 0,9
“Explicit assignment: 'deformation bands 869 cm-1 ... originating from PA'.”
Characterization of New Polymer Material of Amino–Cyclodextrin and Sodium Alginate for Environmental Purposes DOI: 10.3390/membranes13040447 -
confiance 0,8
“Micro-window centered at 869 cm-1 for HCl retrieval.”
Retrieval of Stratospheric HNO3 and HCl Based on Ground-Based High-Resolution Fourier Transform Spectroscopy DOI: 10.3390/rs13112159
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