What absorbs at 3274 cm⁻¹ in an FTIR spectrum?
A band near 3274 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
Quick answer
A band near 3274 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.
Possible functional-group assignments
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| Hydroxyl (O-H) | 8 | 8 | 1.0 |
| N h | 4 | 4 | 1.0 |
| Alkyl C-H | 2 | 2 | 1.0 |
| Secondary amine | 1 | 1 | 1.0 |
| C#c | 1 | 1 | 1.0 |
| Thiol | 1 | 1 | 1.0 |
| Carbohydrate | 1 | 1 | 1.0 |
| C c single bond | 1 | 1 | 1.0 |
| Amide | 1 | 1 | 1.0 |
Ranking reflects accumulated literature evidence, not a single fixed rule. Always confirm against your sample context.
Possible materials
| Material | Supporting peaks | Overlapping groups | Cited sources |
|---|---|---|---|
| starch | 3274, 1650, 1540 | Hydroxyl (O-H), Alkyl C-H | 2 |
| PVA | 3274, 1660, 2930 | Alkyl C-H, Hydroxyl (O-H) | 1 |
| chitosan | 3274, 1650, 1655 | Alkyl C-H, 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 3274 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.
Literature behind these assignments
-
Amide confidence 1.0
“Amide-A band (3274”
Characterization of emulsion films prepared from soy protein isolate at different preheating temperatures DOI: 10.1016/j.jfoodeng.2021.110697 -
Hydroxyl (O-H) confidence 1.0
“They were again left in the surface an absorption peak at 3274 3198 due to -OH conditioning room until their weights were constant.”
Synthesis and characterization of Dioscorea hispida sp. tuber starch-polyacrylamide wood coating and its facile inhibitory towards Pycnoporus sanguineus and Coptotermes curvignathus DOI: 10.1016/j.porgcoat.2016.05.022 -
C c single bond confidence 1.0
“PPy-NiO (50%) hybrid nanocomposite which suggests that N-C stretching band at C-C 3274 S.R.”
Nalage 等 - 2013 - Polypyrrole-NiO hybrid nanocomposite Structural, DOI: 10.1016/j.measurement.2013.06.049 -
Hydroxyl (O-H) confidence 1.0
“The new band is appeared at 3274 which is associated with hydrogen-bonded hydroxyls on the starch molecules in UPS.”
Pourmohammadi 和 Abedi - 2020 - The effect of pre and post-ultrasonication on the DOI: 10.1016/j.ijbiomac.2020.06.205 -
confidence 1.0
“cm-1 The literature attributes the peak 3274 cm-1 to the vibrational elongation of N-H and The literature attributes the peak 3274 to the vibrational elongation of N-H and O-H of the intermolecular and intramolecular bonds of the hydrogen b”
Chitosan/PVA Based Membranes Processed by Gamma Radiation as Scaffolding Materials for Skin Regeneration DOI: 10.3390/membranes11080561 -
Hydroxyl (O-H) confidence 1.0
“LLM confirmed rule peak-group candidate”
Mechanical and Physicochemical Properties of Composite Biopolymer Films Based on Carboxymethyl Cellulose from Young Palmyra Palm Fruit Husk and Rice Flour DOI: 10.3390/polym14091872 -
confidence 1.0
“explicit assignment”
Fabrication of Hypericin Imprinted Polymer Nanospheres via Thiol-Yne Click Reaction DOI: 10.3390/polym9100469 -
confidence 1.0
“The cm(cid:1)1) reflected group frequency region (4000-1800 that the Percent Yield cm(cid:1)1 -OH characteristic broad peak at 3274 was due to N-H stretching (mainly of polyphenols) and stretching of About 2.6 kg plant material yielded 364”
Rasheed 和 Jabeen - 2022 - Pharmacological Role of Capparis decidua (Forssk.) DOI: 10.1177/15593258221123672
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