What absorbs at 2915 cm⁻¹ in an FTIR spectrum?
A band near 2915 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 2915 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 |
|---|---|---|---|
| Alkyl C-H | 39 | 36 | 1,0 |
| Hydroxyl (O-H) | 4 | 4 | 1,0 |
| Water (H2O) | 3 | 3 | 1,0 |
| Methacrylate | 3 | 3 | 1,0 |
| Acetate | 3 | 3 | 1,0 |
| Carbohydrate | 3 | 3 | 1,0 |
| Methoxy (OCH3) | 2 | 2 | 1,0 |
| C-O single bond | 2 | 2 | 1,0 |
| Secondary amine | 2 | 2 | 1,0 |
| N h | 2 | 2 | 1,0 |
| Amide | 2 | 2 | 1,0 |
| Lipid | 1 | 1 | 1,0 |
| Protein | 1 | 1 | 1,0 |
| Aromatic ring | 1 | 1 | 1,0 |
| Alkene (C=C) | 1 | 1 | 1,0 |
| Chlorine | 1 | 1 | 1,0 |
| Methyl | 1 | 1 | 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 |
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 |
|---|---|---|---|
| PVA | 2915, 1660, 2930 | Alkyl C-H, Hydroxyl (O-H), Methacrylate | 1 |
| ZnO | 2915, 1400, 3430 | Hydroxyl (O-H), Alkyl C-H, Methacrylate | 1 |
| calcite | 2915, 2850, 2864 | Methacrylate, Hydroxyl (O-H), Alkyl C-H | 1 |
| apatite | 2915, 3053, 1640 | Hydroxyl (O-H), Alkyl C-H, Water (H2O) | 1 |
| microplastics | 2915, 1643, 1614 | Alkyl C-H, Hydroxyl (O-H), Methacrylate | 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 2915 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
-
Alkyl C-H încredere 1,0
“Explicit assignment: νas(CH2)”
Molecular characterization of silver-stearate (AgStNPs) nanoparticles: A hydrophobic and antimicrobial material against foodborne pathogens DOI: 10.1016/j.foodres.2015.08.005 -
Alkyl C-H încredere 1,0
“In particular, for PE at 710 and 719 cm-1 (-CH2 rocking deformation), 2847 and 2915 cm-1 (- symmetric and asymmetric stretching), 1462 and 1472 cm-1 (-CH=CHstretching) CH2 [36].”
Campanale 等 - 2023 - Fourier Transform Infrared Spectroscopy to Assess DOI: 10.3390/polym15040911 -
Carbohydrate încredere 1,0
“Moreover, two bands at 2915 and 2850 were linked to pectin and extractives, cm-1 such as waxes [33].”
Effects of Wet and Dry Treatments on Surface Functional Groups and Mechanical Properties of Flax Fiber Composites DOI: 10.3390/coatings13061036 -
Alkyl C-H încredere 1,0
“In the IR spectra of TG, the cm-1 broad band approximately 3300 is attributed to O-H stretching vibration due to hydrogen bonding involving the hydroxyl groups on the gum molecules, whereas the cm-1 band at 2915 is attributed to CH symmetri”
Santos 等 - 2019 - Physicochemical, thermal and rheological propertie DOI: 10.1016/j.ijbiomac.2019.05.025 -
Alkyl C-H încredere 1,0
“A peak at 2915 is assigned to C-H (asymmetforth by other isoconversional expressions for some differcm-1 ric) stretching vibration [30].”
Optical, electrical, mechanical, and thermal properties and non-isothermal decomposition behavior of poly(vinyl alcohol)–ZnO nanocomposites DOI: 10.1007/s13726-020-00806-8 -
Amide încredere 1,0
“Additionally, cm-1 Band / Vibration bands related with proteins (secondary amide) can be 2915 CH symmetric stretch (long aliphatic C chains)”
de Souza 等 - 2022 - Diffuse Reflectance FTIR of Latent Fingerprints an DOI: 10.21577/0103-5053.20220150 -
Alkyl C-H încredere 1,0
“responsible for the IR peaks at 2915 and 3436 cm-1, The spectra of the treated apatite show new bands at 2922 and 2848 which are associated with the -CH and -CH groups in SNLS, as well as two additional bands at 2 3 cm-1, 1631 and 1609 attr”
Abdel-Halim 等 - 2023 - Apatite-Calcite Flotation Separation Using Sodium DOI: 10.3390/min13070970 -
Acetate încredere 1,0
“Peaks seemingly due to O-H stretch appeared at 3460 cm-1, cm-1, C-H stretch (aromatic) at 2915 C=O stretch due to vinyl acetate at 1730 C=O at 1727 cm-1, 1610 cm-1, 778 cm-1, 1517 cm-1, and 756 cm-1 corresponds to crystalline form”
How to Improve Solubility and Dissolution of Irbesartan by Fabricating Ternary Solid Dispersions: Optimization and In-Vitro Characterization DOI: 10.3390/pharmaceutics14112264
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