What absorbs at 799 cm⁻¹ in an FTIR spectrum?
A band near 799 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 799 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 |
|---|---|---|---|
| Silicon-oxygen (Si-O) | 8 | 8 | 1,0 |
| Alkyl C-H | 4 | 4 | 1,0 |
| Siloxane (Si-O-Si) | 3 | 3 | 1,0 |
| Silicon (Si) | 3 | 3 | 1,0 |
| C-O single bond | 2 | 2 | 1,0 |
| Metal oxygen | 1 | 1 | 1,0 |
| C c single bond | 1 | 1 | 1,0 |
| Methoxy (OCH3) | 1 | 1 | 1,0 |
| Methacrylate | 1 | 1 | 1,0 |
| Acetate | 1 | 1 | 1,0 |
| Hydroxyl (O-H) | 1 | 1 | 1,0 |
| Fluorine (C-F) | 1 | 1 | 0,9 |
| Boron nitrogen | 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 |
|---|---|---|---|
| silica | 799, 1100, 1080 | Silicon-oxygen (Si-O), Silicon (Si), Siloxane (Si-O-Si) | 2 |
| hematite | 799, 1030, 469 | Silicon-oxygen (Si-O), Siloxane (Si-O-Si), Silicon (Si) | 2 |
| TiO2 | 799, 1700, 1093 | Alkyl C-H | 1 |
| CaO | 799, 2909, 1839 | Silicon-oxygen (Si-O) | 1 |
| TiO | 799, 1730, 1699 | Alkyl C-H | 1 |
| kaolinite | 799, 3696, 693 | Silicon-oxygen (Si-O), Silicon (Si), Siloxane (Si-O-Si) | 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 799 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
-
Silicon (Si) confiance 1,0
“4 SEM micrograph of 2-AKC at × 500 and × 1000 magnifications cm-1, cm-1 cm-1 The peaks at 799.10 757.78 and 797.78 were assigned to the Si-O stretching of the kaolin clay type.”
Preparation and characterization of adsorbents derived from bentonite and kaolin clays DOI: 10.1007/s13201-018-0827-2 -
C-O single bond confiance 1,0
“FTIR spectroscopy Mössbauer spectroscopy d-OH indicated that goethite of type 1 is characterized by the presence of the band between 799 Iron ores 802cm(cid:3)1, 904cm(cid:3)1 c-OH the between 898 and and the bulk hydroxyl stretch between 3”
Spectroscopic characterization of iron ores formed in different geological environments using FTIR, XPS, Mössbauer spectroscopy and thermoanalyses DOI: 10.1016/j.saa.2014.10.090 -
confiance 1,0
“Bending H-O-H viclay spectra, Si-O vibrations at wavenumber bration occurs in the area between 600-950 799 cm-1 indicate the presence of quartz minercm-1.”
Natural Clay of Pasaman Barat Enriched by CaO of Chicken Eggshells as Catalyst for Biodiesel Production DOI: 10.9767/bcrec.15.3.8097.662-673) -
Silicon-oxygen (Si-O) confiance 1,0
“The doublet cm(cid:1)1 cm(cid:1)1 superficial corresponds to the dermis containing many absorption bands at 799 and 776 due to the cm(cid:1)1 a-quartz SieOeSi granulomas.”
Detection of silica and calcium carbonate deposits in granulomatous areas of skin sarcoidosis by Fourier transform infrared spectroscopy and Field Emission Scanning Electron Microscopy coupled with Energy Dispersive X-ray Spectroscopy analysis DOI: 10.1016/j.crci.2016.05.007 -
Acetate confiance 1,0
“The band cm-1 recorded at 799 is ascribed to the C-O stretching vibrations.”
Kannan 等 - 2023 - Exploration of third order nonlinear optical featu DOI: 10.15251/DJNB.2023.181.367 -
Alkyl C-H confiance 1,0
“These observations are mainly due to the overlapping with the weak peak peak at 799 cm-1 which is designated as the CH2 rocking mode of PAA.”
Liew 等 - 2016 - Poly(Acrylic acid)-Based Hybrid Inorganic-Organic DOI: 10.3390/polym8050179 -
Silicon (Si) confiance 1,0
“cm-1(Si-O-Si cm-1 cm-1 symmetrical stretching vibration) and at 693 and 469 (Si-O-Si symmetrical at 777 and 799 cm-1(Si-O-Si symmetrical stretching vibration) and at 693 cm-1 and 469 cm-1 (Si-O-Si and asymmetrical bending vibration, overlap”
Ma 等 - 2019 - Investigation of the Optical, Physical, and Chemic DOI: 10.3390/su11143803 -
Silicon (Si) confiance 1,0
“After the first step, cm-1 cm-1 and 465 (SI-Or1), the bands centered at 799 related to Si-O-Si bonds disappeared which confirms that”
Marin 等 - 2015 - Revalorization of Rice Husk Waste as a Source of C DOI: 10.1007/s12221-015-0285-5
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