What absorbs at 1181 cm⁻¹ in an FTIR spectrum?
A band near 1181 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
Răspuns rapid
A band near 1181 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.
Atribuiri posibile ale grupelor funcționale
| Grup funcțional | Fapte suport | Surse citate | Încredere maximă |
|---|---|---|---|
| Methacrylate | 5 | 5 | 1,0 |
| C-O single bond | 5 | 5 | 1,0 |
| Acetate | 5 | 5 | 1,0 |
| Methoxy (OCH3) | 4 | 4 | 1,0 |
| Amide | 2 | 2 | 1,0 |
| Ketone | 1 | 1 | 1,0 |
| Ester | 1 | 1 | 1,0 |
| Carboxyl (COOH) | 1 | 1 | 1,0 |
| Carbonyl (C=O) | 1 | 1 | 1,0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1,0 |
| Silicon (Si) | 1 | 1 | 1,0 |
| N h | 1 | 1 | 1,0 |
| Hydroxyl (O-H) | 1 | 1 | 1,0 |
| Oxygen heterocycle | 1 | 1 | 1,0 |
| Alkyl C-H | 1 | 1 | 1,0 |
| C c single bond | 1 | 1 | 1,0 |
Clasamentul reflectă dovezile acumulate din literatură, nu o singură regulă autoritară. Confirmați întotdeauna în contextul mostrei dvs.
Materiale posibile
| Material | Vârfuri suport | Grupuri suprapuse | Surse citate |
|---|---|---|---|
| epoxy resin | 1181, 905, 1100 | Methacrylate, Acetate, Methoxy (OCH3) | 1 |
| keratin | 1181, 1635, 1717 | Methacrylate, Acetate | 1 |
| PMMA | 1181, 1722, 1383 | Methacrylate, Acetate, Methoxy (OCH3) | 1 |
Materialele sunt afișate numai atunci când același grup de literatură susține această bandă și cel puțin un vârf caracteristic suplimentar.
Logica spectrului
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 1181 cm⁻¹ is usually not enough for material identification by itself.
Utilizare în condiții reale
Acest tip de interogare este comun în identificarea polimerilor, screeningul materialelor plastice necunoscute, depanarea QC, verificarea materialelor reciclate și revizuirea atribuirii vârfurilor bazată pe literatură.
Greșeli comune
- Tratarea unei benzi izolate ca dovadă a unui material fără a verifica cel puțin unul sau două vârfuri de susținere.
- Ignorând suprapunerea: mai multe grupuri funcționale pot contribui în apropierea aceluiași număr de undă.
- Omiterea validării atunci când aditivii, amestecurile, oxidarea sau contaminarea pot distorsiona spectrul.
Sfat de verificare
Când ambiguitatea rămâne, validați ipoteza prin DSC, GC-MS sau TGA, în special pentru amestecuri, probe degradate și polimeri umpluți.
Literatura din spatele acestor atribuiri
-
C c single bond încredere 1,0
“carbon).37a,b stretching, where the apex denotes a chain bance-frequency spectrum, when the data are collected cm-1 cm-1 A peak at 1181 has contributions from aromatic at a nominal resolution of 4 (see Figure 2 and C-C¢ C-H in-plane bending”
Musto 等 - 2005 - Host-guest interactions and crystalline structure DOI: 10.1021/ma0477899 -
Acetate încredere 1,0
“Figure 8(b) shows that the peaks observed at 1064 maycorrespondto-C-O-C-,whilepeaksobservedbetween1181.33cm(cid:6)1 binding density that characterizes the number of non-electronic-sharing cm(cid:6)1 C-O interactions between atoms such as io”
Optical characterizations of PMMA/metal oxide nanoparticles thin films: bandgap engineering using a novel derived model DOI: 10.1016/j.heliyon.2021.e05952 -
Oxygen heterocycle încredere 1,0
“The decrease of the absorption band near 1181 cm-1, which was derived from the bridge between the benzene rings [40], indicates that the backbone chains of epoxy resin can be cut by thermal aging.”
Reinforced Structure Effect on Thermo-Oxidative Stability of Polymer-Matrix Composites: 2-D Plain Woven Composites and 2.5-D Angle-Interlock Woven Composites DOI: 10.3390/polym14173454 -
Hydroxyl (O-H) încredere 1,0
“0.6 3523cm-1 3000 , O-H deformation vibrastretching vibration at 1441cm-1 1181cm-1 tion at”
Li 和 Yang - 2014 - Fabrication and Characterization of Electrospun Wo DOI: 10.1155/2014/163678 -
încredere 1,0
“cm-1 2847 cm-1 due to the alkyl groups, a peak at 1648 cm-1 related to the N-H bending belonging to -NH2 2847 due to the alkyl groups, a peak at 1648 related to the N-H bending belonging to -NH 2 cm-1 groups, and peaks at around 1181 and 10”
Acrylic Pressure-Sensitive Adhesive Reinforced with Aluminum Nitride and Its Thermal Properties: Effect of Surface Treatment and Particle Size DOI: 10.3390/coatings10020188 -
Acetate încredere 1,0
“1181 which is the C-O stretching in -CH-O and micro (< 2 mm) residues.”
Degradation of Film and Rigid Bioplastics During the Thermophilic Phase and the Maturation Phase of Simulated Composting DOI: 10.1007/s10924-021-02098-2 -
Acetate încredere 1,0
“cm-1 cm-1, cm-1, In addition, the most significant absorptions are observed at 1737 and 1092 1181 cm-1 1274 corresponding to the C=O and C-O-C respectively [12], indicating the existence of ester 1H group.”
Wen 等 - 2018 - A novel oligomer containing DOPO and ferrocene gro DOI: 10.1016/j.polymdegradstab.2018.08.010 -
Acetate încredere 1,0
“The absorption peak at 1181 was the anti-symmetric stretching of the C-O-C of the ester substance [47].”
Nano Catalysis of Biofuels and Biochemicals from Cotinus coggygria Scop. Wood for Bio-Oil Raw Material DOI: 10.3390/polym14214610
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