What absorbs at 1489 cm⁻¹ in an FTIR spectrum?
A band near 1489 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 1489 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 |
|---|---|---|---|
| Nitrogen heterocycle | 3 | 3 | 1,0 |
| C-O single bond | 3 | 3 | 1,0 |
| Aromatic ring | 3 | 3 | 1,0 |
| Methoxy (OCH3) | 2 | 2 | 1,0 |
| Methacrylate | 2 | 2 | 1,0 |
| Acetate | 2 | 2 | 1,0 |
| Ring structure | 2 | 2 | 1,0 |
| Hydroxyl (O-H) | 1 | 1 | 1,0 |
| Silicon (Si) | 1 | 1 | 1,0 |
| Lewis acid site | 1 | 1 | 1,0 |
| Secondary amine | 1 | 1 | 1,0 |
| C n single bond | 1 | 1 | 1,0 |
| Amide | 1 | 1 | 1,0 |
| Alkyl C-H | 1 | 1 | 1,0 |
| Alkene (C=C) | 1 | 1 | 1,0 |
| C=n | 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 |
|---|---|---|---|
| GO | 1489, 1720, 1182 | C-O single bond, Methoxy (OCH3) | 1 |
| DNA | 1489, 1712, 1660 | C-O single bond, Methoxy (OCH3) | 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 1489 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
-
C=n confiance 1,0
“cm-1 absorbance of the IR band at 3604 The decrease of the absorbance of the IR band at 1489 indicates a -C=N-benzene smaller weight of the ring vibrational mode after the interaction of the GO sheets with PDITC, this being in good agreemen”
Baibarac 等 - 2019 - Adsorption of 1,4-phenylene diisothiocyanate onto DOI: 10.1038/s41598-019-48314-x -
Alkene (C=C) confiance 1,0
“Following here, another distinct peak can be seen at Elemental Analysis cm-1, 1489 indicating the C=C vibrations of the aromatic ring [19].”
Bohari 等 - 2022 - Synthesis and Characterization of 2,4-Dichlorophen DOI: 10.22146/ijc.73546 -
Ring structure confiance 1,0
“Adenine,Guanine Base/in-planevibration 1420 1420 [19] Adenine, Guanine Ring vibration, C=N 1489 1489 [21] Adenine,Guanine dA,dGanti”
Han 等 - 2018 - Insight into Rapid DNA-Specific Identification of DOI: 10.3390/molecules23112842 -
Ring structure confiance 1,0
“In the second region, the prominent absorption bands at cm-1 1489 and 1420 were due to the ring vibrations of adenine and guanine (Froehlich”
A novel FTIR discrimination based on genomic DNA for species-specific analysis of meat and bone meal DOI: 10.1016/j.foodchem.2019.05.088 -
C-O single bond confiance 1,0
“But the position of benzene ring C = C stretching vibration absorption peak and =C-O-C asymmetric stretching vibration absorption peak occurred shift 1485cm-1 1489cm-1”
Li 等 - 2011 - The detection of Cypermethrin on the surface of Ap DOI: 10.4028/www.scientific.net/AMR.287-290.2991 -
Alkyl C-H confiance 1,0
“(CH asymmetric and symmetric stretching 2 cm-1 cm-1 (C-H (-C-H vibrations), 1489 bending in CH 2), 1435 Shore A hardness cm-1 (C-O (cis-) bending (rocking)), 1105 (aliphatic saturated”
Bhullar 等 - 2021 - Advanced spectroscopy, microscopy, diffraction and DOI: 10.1039/d0py01348j -
Lewis acid site confiance 1,0
“cm-1) contained both bands of pyridine coordinated to Lewis sites (1608, 1489 and 1446 and pyridinium cations formed by reaction of pyridine with Brønsted sites (1640, 1547 and 1489 cm-1).”
Unravelling water effects on solid acidic catalysts: Case study of TiO 2 /SiO 2 for dehydration of isobutanol DOI: 10.1016/j.jcat.2016.12.007 -
confiance 1,0
“The coexistence of Brønsted acid sites (at 1542 cm-1 addition, another peak at about 1489 cm-1 was characteristic of pyridine absorbed on both Lewis and and 1636 cm-1) and Lewis acid sites (at 1453 and 1614 cm-1) are evident for SO42-/Sn-MM”
SO42-/Sn-MMT Solid Acid Catalyst for Xylose and Xylan Conversion into Furfural in the Biphasic System DOI: 10.3390/catal7040118
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