What absorbs at 675 cm⁻¹ in an FTIR spectrum?
A band near 675 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 675 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 | 4 | 4 | 1,0 |
| C-O single bond | 3 | 3 | 1,0 |
| Silicon-oxygen (Si-O) | 2 | 2 | 1,0 |
| Aromatic ring | 2 | 2 | 1,0 |
| C c single bond | 2 | 2 | 1,0 |
| Methoxy (OCH3) | 2 | 2 | 1,0 |
| Methacrylate | 2 | 2 | 1,0 |
| Acetate | 2 | 2 | 1,0 |
| Siloxane (Si-O-Si) | 1 | 1 | 1,0 |
| Silicon (Si) | 1 | 1 | 1,0 |
| N-O bond | 1 | 1 | 1,0 |
| Hydrogen bond | 1 | 1 | 1,0 |
| Amide | 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 |
|---|---|---|---|
| polyurethanes | 675, 1740, 1728 | Alkyl C-H | 1 |
| bitumen | 675, 1625, 810 | Alkyl C-H, Aromatic ring | 1 |
| oil shale | 675, 1625, 1053 | Alkyl C-H, Silicon-oxygen (Si-O), Aromatic ring | 1 |
| chitosan | 675, 1650, 1655 | Alkyl C-H, C-O single bond | 1 |
| gelatin | 675, 1652, 3300 | Alkyl C-H, C-O single bond | 1 |
| hematite | 675, 1030, 469 | Silicon-oxygen (Si-O), 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 675 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
-
Acetate confiance 1,0
“Chem., 2020, 20 (3), 567 - 578 cm-1), cm-1 1470-1340 alkenes (C-H within the range of 995C-O-C asymmetric stretching, C-O 1500-1300 cm-1), cm-1 C-O functional group of alcohol, ether, of C-H bending and C675 stretching;”
Aziz 等 - 2020 - FTIR and HPLC-Based Metabolomics of Yacon Leaves E DOI: 10.22146/ijc.43453 -
Amide confiance 1,0
“interactions.33 Accumulating lines of eviprotein-ligand cm-1 originates band at 675 corroborating the presence dences reported AuNPs pivotal role in rapid biomoleccm-1 nanoparticles44 of Au and an amide I band at 1638 recognition.34(cid:2)3”
Hetero-Functionalized Gold Nanoparticles to Silence AU-Rich Element Containing mRNAs in RAGE-Expressing Inflammatory Cells: Preparation, Characterization, and <i>In</i>-<i>Vitro</i> Evaluation DOI: 10.1166/jnn.2018.14648 -
Acetate confiance 1,0
“10 768, 856, 955, 1265, 1412, 1447, 1667, 2907 and 2968 1085 C-O vibration Lactate [20], 11 cm-1, whereas peaks at 675, 747, 1169, 1225, 1304,”
Zou 等 - 2016 - Whole blood and semen identification using mid-inf DOI: 10.1039/C5AY03337C. -
C c single bond confiance 1,0
“The cm-1, cm-1 strong C-OH band at 1045 C-H band at 850 and C-C band at cm-1 675 show an intense aromatic matrix in the oil shale [24, 26].”
Altun - 2009 - INCIDENTAL RELEASE OF BITUMEN DURING OIL SHALE GRI DOI: 10.3176/oil.2009.3.04 -
Alkyl C-H confiance 1,0
“1102 1102 1027 1027 1042 C-O skeletal stretch - - 929 929 929 C-H deformation vibration (carbohydrate) Fingerprint - - 861 854 854 C-H deformation vibration (carbohydrate) 675 667 659 667 667 C-C Skeletal stretch Table 2.”
Characterization of gelatin/chitosan ploymer films integrated with docosahexaenoic acids fabricated by different methods DOI: 10.1038/s41598-019-44807-x -
confiance 1,0
“In celadonite, the Si-O stretching and cm-1, bending vibrations [72] are seen at 675, 490, 455 and 437 while in glauconite, these cm-1.”
Assessment of Easily Accessible Spectroscopic Techniques Coupled with Multivariate Analysis for the Qualitative Characterization and Differentiation of Earth Pigments of Various Provenance DOI: 10.3390/min12060755 -
C c single bond confiance 1,0
“Besides, peaks at 675 cm(cid:0) 1 C-C-C C-H bending [41].”
Hossain 和 Roy - 2023 - Monitoring the curing efficiency of a plant-based DOI: 10.1016/j.heliyon.2023.e16273 -
Alkyl C-H confiance 1,0
“Between 900 cm-1 and 675 cm-1, axial deformation vibrations, characteristic of the off-plane angular deformation of the C-H bonds of aromatic rings were identified [47].”
Biodegradation Study of Polyurethanes from Linseed and Passion Fruit Oils DOI: 10.3390/coatings12050617
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