What absorbs at 729 cm⁻¹ in an FTIR spectrum?
A band near 729 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 729 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 |
| Carbonate | 2 | 2 | 1,0 |
| N h | 2 | 2 | 1,0 |
| Silicon-oxygen (Si-O) | 2 | 2 | 1,0 |
| Metal oxygen | 2 | 2 | 1,0 |
| Silicon (Si) | 1 | 1 | 1,0 |
| Ring structure | 1 | 1 | 1,0 |
| Aromatic ring | 1 | 1 | 1,0 |
| Carboxyl (COOH) | 1 | 1 | 1,0 |
| Nucleic acid | 1 | 1 | 1,0 |
| Siloxane (Si-O-Si) | 1 | 1 | 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 |
| Alkene (C=C) | 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 |
|---|---|---|---|
| zeolite | 729, 1013, 1245 | Alkyl C-H, Silicon-oxygen (Si-O), N h | 1 |
| Ionic Liquids | 729, 938, 1040 | Alkyl C-H, Silicon-oxygen (Si-O) | 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 729 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
“The cm-1 obtained from the CH absorption band shown at 728.97 2 rocking of the amide chain of the as-spun and drawn ILconfined”
Dawelbeit 和 Yu - 2021 - Tentative Confinement of Ionic Liquids in Nylon 6 DOI: 10.1021/acsomega.0c04740 -
Metal oxygen confiance 1,0
“Two peaks observed at ~729 and ~854 cm-1 are due to the stretching vibration mode of Ce-O-Ce (Cerium -oxygen) with a lower”
Oxygen vacancies and F+ centre tailored room temperature ferromagnetic properties of CeO2 nanoparticles with Pr doping concentrations and annealing in hydrogen environment DOI: 10.1016/j.jallcom.2020.156079 -
Carbonate confiance 1,0
“cm(cid:2)1 cm(cid:2)1, 876 and 885 which are also consistent with the literature.30 cm(cid:2)1 The carbonate peaks at 729 of synthetic n”
Long 等 - 2012 - From synthetic to biogenic Mg-containing calcites DOI: 10.1039/c2cp22453d -
Acetate confiance 1,0
“reported in literature due to the incomplete decomposition of the products and two prominent cm-1 cm-1 peaks appeared at 795 (La-O) and 1316 (C-O) reveals the existence of the oxalate ion cm-1 cm-1 while in this research work these peaks ap”
Study of structural, optical and electrical properties of La3+ doped Mg0.25 Ni0.15 Cu0.25 Co0.35 Fe2-x Lax O4 spinel ferrites DOI: 10.1016/j.physb.2020.412565 -
Metal oxygen confiance 1,0
“(Si-O-Si and Al-O-Si) Symmetric stretching vibration 729 721 720 721 716 714 722 (Si-O-Si and Al-O-Si) Symmetric stretching vibration of Si-O-Si(Al) 795 796 795 795 794 793”
Bohacs 等 - 2017 - CONTROL OF NATURAL ZEOLITE PROPERTIES BY MECHANICA DOI: 10.1515/amm-2017-0216 -
Alkyl C-H confiance 1,0
“267 cm-1, vibrations of aromatic rings, bands at 1486 and 1469 associated with CH and CH 268 3 2 cm-1, deformations, respectively and a band at 729 related to (CH 2) in-phase rocking,”
Franca 等 - 2020 - Monitoring diclofenac adsorption by organophilic a DOI: 10.1016/j.envpol.2013.04.012 -
Nucleic acid confiance 1,0
“Similar changes, although less pronounced, can be seen in other nucleic acid bands at 785 and 729 cm-1.”
Kochan 等 - 2020 - Vibrational Spectroscopy as a Sensitive Probe for DOI: 10.3390/s20123452 -
Alkyl C-H confiance 1,0
“The chemical compoThe absorption band at 729.08 is attributed to the out of C-H N-H sition of the as-synthesized cationic surfactants (HBT, DBT and the plane bending for the aromatic structure.”
The synthesis and characterization of benzotriazole-based cationic surfactants and the evaluation of their corrosion inhibition efficiency on copper in seawater DOI: 10.1039/c9ra04461b
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