What absorbs at 3268 cm⁻¹ in an FTIR spectrum?
A band near 3268 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
Quick answer
A band near 3268 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.
Mulige funktionelle gruppetildelinger
| Funktionel gruppe | Understøttende fakta | Citerede kilder | Højeste tillid |
|---|---|---|---|
| Hydroxyl (O-H) | 4 | 4 | 1,0 |
| N h | 3 | 3 | 1,0 |
| Hydrogen bond | 1 | 1 | 1,0 |
| Methoxy (OCH3) | 1 | 1 | 1,0 |
| Methacrylate | 1 | 1 | 1,0 |
| C-O single bond | 1 | 1 | 1,0 |
| Acetate | 1 | 1 | 1,0 |
| Alkyl C-H | 1 | 1 | 1,0 |
| Aromatic ring | 1 | 1 | 1,0 |
Rangering afspejler akkumulerede litteraturbeviser, ikke en enkelt autoritativ regel. Bekræft altid mod din prøvekontekst.
Possible materials
| Materiale | Understøttende toppe | Overlapping groups | Citerede kilder |
|---|---|---|---|
| hydrogel | 3268, 1632, 1062 | Hydroxyl (O-H), N h | 1 |
Materials are shown only when the same literature pool supports this band and at least one additional characteristic peak.
Spectrum logic
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 3268 cm⁻¹ is usually not enough for material identification by itself.
Real-world usage
This type of query is common in polymer identification, unknown plastic screening, QC troubleshooting, recycled-material verification, and literature-backed peak assignment review.
Common mistakes
- Treating one isolated band as proof of a material without checking at least one or two supporting peaks.
- Ignoring overlap: multiple functional groups can contribute near the same wavenumber.
- Skipping validation when additives, blends, oxidation, or contamination may distort the spectrum.
Verification advice
When ambiguity remains, validate the hypothesis with DSC, GC-MS, or TGA, especially for blends, degraded samples, and filled polymers.
Litteratur bag disse tildelinger
-
Aromatic ring tillid 1,0
“An 1477cm-1, 1573cm-1, 3316cm-1 bending vibrations between 3268 and aromatic C-H gives bands at and and be-”
Alkurdi 等 - 2022 - Development and Evaluation of a Novel Polymer Drug DOI: 10.1155/2022/7903310 -
Hydroxyl (O-H) tillid 1,0
“LLM confirmed rule peak-group candidate”
Lauroylated, Acetylated, and Succinylated Agave tequilana Fructans Fractions: Structural Characterization, Prebiotic, Antibacterial Activity and Their Effect on Lactobacillus paracasei under Gastrointestinal Conditions DOI: 10.3390/polym15143115 -
N h tillid 1,0
“The maximum at 3243 cm-1 which corresponds to symmetric valence vibrations of N-H bonds from the sulfonamide NH2 group was shifted for 25 units in relation to its position in the sulfanilamide spectrum (3268 cm-1).”
Modified Sulfanilamide Release from Intelligent Poly(N-isopropylacrylamide) Hydrogels DOI: 10.3390/pharmaceutics15061749 -
tillid 1,0
“O-H total sugars in the SFS solution, Figure 1 presents only the peak at around 3268 This peak is assigned to N-H sucrose and stachyose reactions.”
Patil 和 Netravali - 2019 - Enhancing Strength of Wool Fiber Using a Soy Flour DOI: 10.1021/acsomega.9b00055 -
Hydroxyl (O-H) tillid 1,0
“As can be seen, cm-1 cm-1 a shift and a decrease in band intensity from 3268 to 3200 (O-H and N-H a shift and a decrease in band intensity from 3268 cm-1 to 3200 cm-1 (O-H and N-H groups)”
Evaluation of Chemical Changes in Laboratory-Induced Colistin-Resistant Klebsiella pneumoniae DOI: 10.3390/ijms22137104 -
Hydroxyl (O-H) tillid 0,9
“Same assignment as above.”
Development and Characterization of Biosorbent Film from Eggshell/Orange Waste Enriched with Banana Starch DOI: 10.3390/polym15112414 -
Hydroxyl (O-H) tillid 0,8
“Described as O-H vibration peak.”
Improvement of the textural characteristics of curdlan gel by the formation of hydrogen bonds with erythritol DOI: 10.1016/j.foodhyd.2021.106648
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