What absorbs at 1185 cm⁻¹ in an FTIR spectrum?
A band near 1185 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 1185 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 |
|---|---|---|---|
| C-O single bond | 4 | 4 | 1,0 |
| Methoxy (OCH3) | 3 | 3 | 1,0 |
| Methacrylate | 3 | 3 | 1,0 |
| Acetate | 3 | 3 | 1,0 |
| Alkyl C-H | 3 | 2 | 1,0 |
| Secondary amine | 2 | 2 | 1,0 |
| Amide | 2 | 2 | 1,0 |
| Amine primary | 1 | 1 | 1,0 |
| N h | 1 | 1 | 1,0 |
| Nucleic acid | 1 | 1 | 1,0 |
| Phosphorus | 1 | 1 | 1,0 |
| Phosphate (PO4) | 1 | 1 | 1,0 |
| Carbohydrate | 1 | 1 | 1,0 |
| C n single bond | 1 | 1 | 1,0 |
| Sulfate (SO4) | 1 | 1 | 0,8 |
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 |
|---|---|---|---|
| gelatin | 1185, 1652, 3300 | Methacrylate, Acetate, C-O single bond | 1 |
| polypyrrole | 1185, 1700, 400 | Methacrylate, Acetate | 1 |
| DNA | 1185, 1712, 1660 | Methacrylate, Acetate, 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 1185 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
“with a remote attenuated total reflectance (ATR) probe for realmonitoring.17 However, they point out that overlapping time cm-1 C-O-C polymer absorbances at 1185 (asymmetric C-H vibration24) stretching vibration and asymmetric rocking”
Braun 等 - 2006 - Infrared spectroscopic determination of lactide co DOI: 10.1021/ma061922a -
Amide confiance 1,0
“the cm-1 cm-1 peak at 1185 is due to C-N stretching;”
Thakur 和 Lokhande - 2018 - Morphological Modification for Optimum Electrochem DOI: 10.4152/pea.201806377 -
Acetate confiance 1,0
“The band at 1185 cm-1 attributed for C-O stretching vibrations of ether groups results from carboxymethylation of cellulose or ether linkage of cellulose compartment in combination with that arising from the two”
Ahmed 等 - 2021 - STRUCTURAL AND OPTICAL CHARACTERISTICS OF POLY(VIN DOI: 10.4314/bcse.v35i3.12 -
Alkyl C-H confiance 1,0
“1667, 1595 1650, 1620, 1590 H 2O bending 1508, 1458 C-H vibration 1185, 816, 759, 577”
Lacalamita - 2018 - Micro-FTIR and EPMA Characterisation of Charoite f DOI: 10.1155/2018/9293637 -
Phosphate (PO4) confiance 1,0
“In the A-DNA infrared spectrum contains a new band at cm-1 case of nucleic acids, water and hydrated ions neu1185 assigned to the vibrations of deoxyribose tralize electrostatic repulsions between phosphate in the C3′-endo conformation [5],”
Olsztynska-Janus 等 - 2012 - Spectroscopic techniques in the study of human tis DOI: 10.5277/abb120314 -
Acetate confiance 1,0
“deformation of CH was evidenced at peak ~ 1364 At 3 cm-1 cm-1 ~ 1185 is the stretching of C-O-C and at ~ 1031 Statistic analysis”
Paraiso 等 - 2020 - Hibiscus sabdariffa L. extract Characterization ( DOI: 10.9755/ejfa.2020.v32.i1.2059 -
Acetate confiance 1,0
“4 cm-1, cm-1 stretching C=C at 1595 and 1500 stretching C-O at 1185 and bending C-H at 878, 757 5 6”
Spepi 等 - 2016 - Experimental and DFT Characterization of Halloysit DOI: 10.1517/17425247.2016.1169271. -
N h confiance 1,0
“C=S, vibration or N-C-N stretching vibration (1424 C-N, or NH rocking vibration (1185 2”
Synthesis and Characterization of Cu2FeSnS4–Cu2MnSnS4 Solid Solution Microspheres DOI: 10.3390/ma13194440
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