What absorbs at 649 cm⁻¹ in an FTIR spectrum?
A band near 649 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 7 cited sources
Snel antwoord
A band near 649 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 | 2 | 2 | 1,0 |
| Acetate | 2 | 2 | 1,0 |
| N-O bond | 1 | 1 | 1,0 |
| C c single bond | 1 | 1 | 1,0 |
| Methoxy (OCH3) | 1 | 1 | 1,0 |
| C-O single bond | 1 | 1 | 1,0 |
| Hydroxyl (O-H) | 1 | 1 | 1,0 |
| Ketone | 1 | 1 | 1,0 |
| Ester | 1 | 1 | 1,0 |
| Carboxyl (COOH) | 1 | 1 | 1,0 |
| Amide | 1 | 1 | 1,0 |
| Carbonyl (C=O) | 1 | 1 | 1,0 |
| Silicon (Si) | 1 | 1 | 1,0 |
| Adsorbed carbon monoxide | 1 | 1 | 1,0 |
| Borate | 1 | 1 | 1,0 |
| N h | 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 |
|---|---|---|---|
| lipids | 649, 1735, 810 | 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 649 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
-
Borate vertrouwen 1,0
“2017).Inalgal cellsbeforebiosorption cm-1 SEM images have clearly shown that Oocystis solitaria samof lithium, the characteristic absorption peak at 649 B-O ples beforeand after lithium biosorption showed different surwhich is assigned to b”
Phycoremediation of lithium ions from aqueous solutions using free and immobilized freshwater green alga Oocystis solitaria: mathematical modeling for bioprocess optimization DOI: 10.1007/s11356-019-05214-x -
Adsorbed carbon monoxide vertrouwen 1,0
“(>99.997 In contrast, as-prepared NiSiBEA sample exhibits a sharp Carbon monoxide purity) was supplied by Linde (>99.0 reduction peak at 649 K and a smaller and broader one at about AG, and nitrogen monoxide purity) was supplied by 785 K (F”
Penkova 等 - 2007 - Effect of the preparation method on the state of n DOI: 10.1021/jp071927p -
vertrouwen 1,0
“bration of Si(Al)-O, the peaks at 787.56 cm-1 and 761.71 cm-1 are assigned to stretching vibration of Si-Si, the peaks at 744.43 cm-1 and 727.85 cm-1 are assigned to stretching vibration of Si-Al(Si), the peaks at 464.98 cm-1 are assigned t”
Effects and Mechanism of Fe3+ on Flotation Separation of Feldspar and Epidote with Sodium Oleate at Natural pH DOI: 10.3390/separations9050110 -
Carbonyl (C=O) vertrouwen 1,0
“The pure NAC molecule showed the main peaks contributed by cm-1), the functional groups of molecules, such as carbonyl -C=O stretching (1,649”
Novel NAC-loaded poly(lactide-co-glycolide acid) nanoparticles for cataract treatment: preparation, characterization, evaluation of structure, cytotoxicity, and molecular docking studies DOI: 10.7717/peerj.4270 -
Hydroxyl (O-H) vertrouwen 1,0
“The broad band between 2900 and cm-1 3600 represents the stretch of the O-H bond, the band at cm-1 1045 indicates a C-O stretch anti-symmetrically coupled to cm-1 the C-C stretch, and the band at 649 is the O-H wag, all of these bands are c”
Research on Misfiring Fault Diagnosis of Engine Based on Wavelet Analysis DOI: 10.25165/j.ijabe.20181105.3748 -
N-O bond vertrouwen 1,0
“Only one thermal decomposition peak appears at 649 C, corresponding to the peak Being an already carbonized material, BC underwent no significant weight loss during the 0.2%/min, T-5% of and the final carbon residue rate was 91.4%.”
Development of Biodegradable Flame-Retardant Bamboo Charcoal Composites, Part II: Thermal Degradation, Gas Phase, and Elemental Analyses DOI: 10.3390/polym12102238 -
N h vertrouwen 0,9
“-NH wagging vibration”
Lu 等 - 2014 - Facile synthesis and characterization of polyethyl DOI: 10.3892/mmr.2014.1906
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