What absorbs at 945 cm⁻¹ in an FTIR spectrum?
A band near 945 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
Snel antwoord
A band near 945 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.
Mogelijke functionele-groeptoewijzingen
| Functionele groep | Ondersteunende feiten | Geciteerde bronnen | Hoogste vertrouwen |
|---|---|---|---|
| C-O single bond | 5 | 5 | 1,0 |
| Methoxy (OCH3) | 4 | 4 | 1,0 |
| Methacrylate | 4 | 4 | 1,0 |
| Acetate | 4 | 4 | 1,0 |
| Silicon-oxygen (Si-O) | 4 | 4 | 1,0 |
| Silicon (Si) | 4 | 4 | 1,0 |
| Hydroxyl (O-H) | 3 | 3 | 1,0 |
| Ring structure | 3 | 3 | 1,0 |
| Silanol (Si-OH) | 3 | 3 | 1,0 |
| Siloxane (Si-O-Si) | 2 | 2 | 1,0 |
| Silicate | 2 | 2 | 1,0 |
| Carbohydrate | 2 | 2 | 1,0 |
| Aromatic ring | 1 | 1 | 1,0 |
| Amide | 1 | 1 | 1,0 |
| Ester | 1 | 1 | 1,0 |
| Metal oxygen | 1 | 1 | 1,0 |
| Water (H2O) | 1 | 1 | 1,0 |
| Fatty acid | 1 | 1 | 1,0 |
| Carboxyl (COOH) | 1 | 1 | 1,0 |
| Alkene (C=C) | 1 | 1 | 0,9 |
Ranglijst weerspiegelt cumulatief literatuurbewijs, niet één gezaghebbende regel. Bevestig altijd aan de hand van uw monsterecontext.
Mogelijke materialen
| Materiaal | Ondersteunende pieken | Overlappende groepen | Geciteerde bronnen |
|---|---|---|---|
| PVC | 945, 834, 1195 | Methoxy (OCH3), Methacrylate, Acetate | 1 |
Materialen worden alleen getoond wanneer dezelfde literatuurpool deze band en ten minste één extra karakteristieke piek ondersteunt.
Spectrumlogica
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 945 cm⁻¹ is usually not enough for material identification by itself.
Gebruik in de praktijk
Dit type query komt vaak voor bij polymeeridentificatie, screening van onbekende kunststoffen, probleemoplossing bij QC, verificatie van gerecycled materiaal en literatuurondersteunde beoordeling van piektoewijzing.
Veelgemaakte fouten
- Het behandelen van een enkele geïsoleerde band als bewijs van een materiaal zonder ten minste een of twee ondersteunende pieken te controleren.
- Overlap negeren: meerdere functionele groepen kunnen bijdragen rond hetzelfde golfgetal.
- Validatie overslaan wanneer additieven, mengsels, oxidatie of verontreiniging het spectrum kunnen verstoren.
Advies voor verificatie
Wanneer dubbelzinnigheid blijft bestaan, valideer de hypothese met DSC, GC-MS of TGA, vooral voor mengsels, gedegradeerde monsters en gevulde polymeren.
Literatuur achter deze toewijzingen
-
Carboxyl (COOH) vertrouwen 1,0
“CdO cm-1, the band in the ester group at 1751 that of 1700 cm-1 CdO cm-1 On the other hand, the Acesulfame-K band at 945 does due to the stretch in carboxylic acids, and the band CdO cm-1 not overlap with any Aspartame band, but the low sig”
Armenta 等 - 2004 - FTIR determination of aspartame and acesulfame-k i DOI: 10.1021/jf049218l -
Fatty acid vertrouwen 1,0
“peak areas between 945 and and peak heights at although various cis and trans fatty acids present in trans fatty acids oil.”
Quantification of trans fatty acid content in French fries of local food service retailers using attenuated total reflection ⠍ Fourier transform infrared spectroscopy DOI: 10.1016/j.foodchem.2010.09.078 -
Silanol (Si-OH) vertrouwen 1,0
“X-raydiffractionspectraofpurePVC, 945cm-1 an absorption peak is seen which could be related nanoparticles, and 4wt% PVC-SiO2 nanocompure SiO2 to the Si-OH group (Si-Ostretching).”
Abdel-Baset 等 - 2016 - Characterization and Optical and Dielectric Proper DOI: 10.1155/2016/1707018 -
Water (H2O) vertrouwen 1,0
“Furthermore, a new peak 945 cm(cid:2)1 43(cid:2) n showed humps when kept in water and further increases in 3PO at 1030 developed.”
Characterisation of the Bioactivity and the Solubility of a New Root Canal Sealer DOI: 10.1016/j.identj.2023.04.003 -
Silicon (Si) vertrouwen 1,0
“however a new band appears at 945 This band can be attributed to Si-O vibration of SiO and it is proved structure21.”
Asmi 等 - 2016 - Synthesis and Characterisation of Composite based DOI: 10.1063/1.4945463 -
Silicon (Si) vertrouwen 1,0
“Infrared analysis of the surface shows cm-1 a peak around 945 which is attributed to silicon hydroxide (Si-OH) bonds present on unfunctionnalized silica nanoparticles [6].”
Brassard 等 - 2012 - Fluorine Based Superhydrophobic Coatings DOI: 10.3390/app2020453 -
Silicate vertrouwen 1,0
“Swedlund's group [35], the maximum IR absorbance at the lowest Si surface concentrations for H2SiO4 in FH suspension occurred at 945 cm-1, and this spectral feature has been attributed to a monomeric silicate surface species.”
Effects of Potassium Loading over Iron–Silica Interaction, Phase Evolution and Catalytic Behavior of Precipitated Iron-Based Catalysts for Fischer-Tropsch Synthesis DOI: 10.3390/catal12080916 -
Carbohydrate vertrouwen 1,0
“cm-1 cm-1, cm-1, and 944.61 are typical for carbohydrates, and the bands at 1632.53 1553.51 and and 944.61 cm-1 are typical for carbohydrates, and the bands at 1632.53 cm-1, 1553.51 cm-1, and 1320.33 cm-1 cm-1 1320.33 can be assigned to ami”
Efficient Degradation of High-Molecular-Weight Hyaluronic Acid by a Combination of Ultrasound, Hydrogen Peroxide, and Copper Ion DOI: 10.3390/molecules24030617
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