What absorbs at 739 cm⁻¹ in an FTIR spectrum?

Réponse rapide

A band near 739 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

Le classement reflète les preuves bibliographiques accumulées, et non une règle faisant autorité. Confirmez toujours dans le contexte de votre échantillon.

Matériaux possibles

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 739 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

  “Meanwhile, numerous strong bands 739 804 cm-1, cm-1, cm-1 863 898 and 1455 in DiaRoot suggested the stretching of C-H groups.”

  Assiry 等 - 2023 - Microstructural and Elemental Characterization of DOI: 10.3390/app13074517
• C c single bond confiance 1,0

  “Meanwhile, the peak at assigned 781, 767, 772, 735, 739 cm-1 corresponded to the C-C stretching vibration of the benzene ring [19].”

  Modification of Hydroxypropyltrimethyl Ammonium Chitosan with Organic Acid: Synthesis, Characterization, and Antioxidant Activity DOI: 10.3390/polym12112460
• Alkyl C-H confiance 1,0

  “As a result of this experiment, we has peaks at 739 769 and cm-1 differently observed colored areas in the reaction tube with 815 assigned to out-of-plane CH bending vibrations orange products accumulated in the region of higher tempertypic”

  Talyzin 等 - 2014 - Hydrogen-Driven Cage Unzipping of C-60 into Nano-G DOI: 10.1021/jp500377s
• Aromatic ring confiance 1,0

  “Besides, the peaks at 1560 and 739 corresponded to stretching vibration of aromatic C=C to the successful modification that the molecular chain of HNH was grafted onto the surface of rGO.”

  One-Step Reduction and Surface Modification of Graphene Oxide by 3-Hydroxy-2-Naphthoic Acid Hydrazide and Its Polypropylene Nanocomposites DOI: 10.3390/nano7020025
• confiance 0,8

  “Same as above.”

  Purification and Glutaraldehyde Activation Study on HCl-Doped PVA–PANI Copolymers with Different Aniline Concentrations DOI: 10.3390/molecules24010063