What absorbs at 1268 cm⁻¹ in an FTIR spectrum?
A band near 1268 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 1268 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 |
|---|---|---|---|
| Methacrylate | 8 | 7 | 1,0 |
| Acetate | 8 | 7 | 1,0 |
| Methoxy (OCH3) | 7 | 6 | 1,0 |
| C-O single bond | 7 | 6 | 1,0 |
| Amide | 3 | 3 | 1,0 |
| Ester | 3 | 2 | 1,0 |
| Carboxyl (COOH) | 3 | 2 | 1,0 |
| Carbonyl (C=O) | 3 | 2 | 1,0 |
| Ketone | 2 | 2 | 1,0 |
| Hydroxyl (O-H) | 2 | 2 | 1,0 |
| Lignin | 2 | 2 | 1,0 |
| Secondary amine | 1 | 1 | 1,0 |
| C n single bond | 1 | 1 | 1,0 |
| N h | 1 | 1 | 1,0 |
| Phosphate (PO4) | 1 | 1 | 1,0 |
| Alkyl C-H | 1 | 1 | 1,0 |
| C c single bond | 1 | 1 | 1,0 |
| Aromatic ring | 1 | 1 | 1,0 |
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 |
|---|---|---|---|
| chitosan | 1268, 1650, 1655 | Acetate, Methacrylate, C-O single bond | 1 |
| methacrylate | 1268, 873, 1725 | Methacrylate, Acetate, C-O single bond | 1 |
| lignin | 1268, 1035, 1510 | Methacrylate, Acetate, C-O single bond | 1 |
| wood | 1268, 1740, 1730 | Methacrylate, Acetate, Methoxy (OCH3) | 1 |
| silver nanoparticles | 1268, 1636, 1631 | Methacrylate, Acetate, C-O single bond | 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 1268 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
-
Acetate vertrouwen 1,0
“The lignin specific FTIR peaks cm-1 noticed at 1268 , depicted the change in lignin's guaicyl ring plus C=O stretch.”
Majeed 等 - 2017 - Lignin macromolecule's implication in slowing the DOI: 10.1002/star.201600362 -
Acetate vertrouwen 1,0
“Although hardwood lignin also contains guacm-1 (12) for syringyl ring and C-O stretch in lignin and iacyl moities, the absorption band at 1268 may have cm-1(13) cm-1.”
Pandey 和 Pitman - 2003 - FTIR studies of the changes in wood chemistry foll DOI: 10.1016/S0964-8305(03)00052-0 -
Acetate vertrouwen 1,0
“The cm-1 peak 1507 could be attributed to an aromatic skeletal of lignin from lignocellulosic cm-1 materials and the medium band at 1268 is attributed to C-O stretching of phenol in lignite”
Optimization of primary sewage sludge and coal lignite by microwave assisted pyrolysis for the production of bio oil DOI: 10.1080/09593330.2020.1797903 -
C-O single bond vertrouwen 1,0
“From the recent degraded sample (A') to the less aged one (B': 19th century), the cm-1 few changes concern the decrease in the intensity band at 1268 related to Car-O of ether group in guaiacyl monomer (methoxyl group branched to aromatic),”
Impact of Natural Degradation on the Aged Lignocellulose Fibers of Moroccan Cedar Softwood: Structural Elucidation by Infrared Spectroscopy (ATR-FTIR) and X-ray Diffraction (XRD) DOI: 10.3390/fermentation8120698 -
Acetate vertrouwen 1,0
“1300-1320 C-O stretch doublet to lower wavenumbers at 1268 and 1245 cm-1 cm-1.”
Modelling ATR-FTIR Spectra of Dental Bonding Systems to Investigate Composition and Polymerisation Kinetics DOI: 10.3390/ma14040760 -
C c single bond vertrouwen 1,0
“The three peaks appearing at 1268, 1390, cm-1 and 2925 are characteristic to C-C, C=C, and C-H stretching vibrations, respectively, proving the presence of alkyl and aryl groups [32,35].”
Fares 等 - 2021 - Influence of Nitrogen-Doped Carbon Dot and Silver DOI: 10.3390/chemosensors9030052 -
Phosphate (PO4) vertrouwen 1,0
“(P-O-C or P-OH stretching), 1268”
Functionalization of poly(glycidylmethacrylate) with iminodiacetate and imino phosphonate groups for enhanced sorption of neodymium - sorption performance and molecular modeling DOI: 10.1016/j.reactfunctpolym.2022.105389 -
Acetate vertrouwen 1,0
“and at 1268 due to cm-1 -C-O-C stretching.”
Kuen 等 - 2017 - Increased Loading, Efficacy and Sustained Release DOI: 10.3390/nano7110379
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