What absorbs at 3394 cm⁻¹ in an FTIR spectrum?
A band near 3394 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 3394 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) | 13 | 12 | 1.0 |
| N h | 6 | 4 | 1.0 |
| Methacrylate | 1 | 1 | 1.0 |
| Ketone | 1 | 1 | 1.0 |
| Ester | 1 | 1 | 1.0 |
| Carboxyl (COOH) | 1 | 1 | 1.0 |
| Carbonyl (C=O) | 1 | 1 | 1.0 |
| Amide | 1 | 1 | 1.0 |
| Acetate | 1 | 1 | 1.0 |
| Hydrogen bond | 1 | 1 | 1.0 |
| Secondary amine | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Nitrogen heterocycle | 1 | 1 | 1.0 |
| Carbohydrate | 1 | 1 | 1.0 |
| Alkene (C=C) | 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 |
|---|---|---|---|
| polypropylene | 3394, 1030, 1600 | Methacrylate, Hydroxyl (O-H) | 2 |
| polyethylene | 3394, 1737, 1720 | Methacrylate, Hydroxyl (O-H) | 1 |
| cellulose | 3394, 1735, 1650 | Methacrylate, Hydroxyl (O-H) | 1 |
| hemicellulose | 3394, 1730, 897 | Methacrylate, Hydroxyl (O-H) | 1 |
| polysaccharides | 3394, 1053, 1143 | Hydroxyl (O-H), Methacrylate | 1 |
| silver nanoparticles | 3394, 1636, 1631 | Hydroxyl (O-H), Methacrylate, 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 3394 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
-
Hydroxyl (O-H) confidence 1.0
“-1 -1 -H peak around 3394 cm correspond to the presence of O stretching from alcohol, 1632 cm is -1 -O -H attributed to H bending, the peak at1328 cm corresponds to Cl.”
Bottom-up approach synthesis of core-shell nanoscale zerovalent iron (CS-nZVI): Physicochemical and spectroscopic characterization with Cu(II) ions adsorption application DOI: 10.1016/j.mex.2020.100976 -
Hydroxyl (O-H) confidence 1.0
“3b), the band near 3394 was In the case of Δ O-H attributed to the presence of the phenolic group that possibly came”
Green synthesis of magnetite nanoparticles using Lathyrus sativus peel extract and evaluation of their catalytic activity DOI: 10.1016/j.clet.2021.100117 -
Hydroxyl (O-H) confidence 1.0
“2θ standard card values The values of 3394cm-1 characteristic band at is attributed to the hydroxyl”
Hybrid structure of biotemplate-zinc-tin oxide for better optical, morphological and photocatalytic properties DOI: 10.1088/1361-6641/aa577c -
Hydroxyl (O-H) confidence 1.0
“FTIR results cm-1 showed decrease in intensity of peaks at 3394, 1716 and 1618 indicating the involvement of O-H, carbonyl group and C=C stretching with the formation of AgNPs with RAE, respectively.”
Voravuthikunchai 等 - 2013 - Green synthesis of silver nanoparticles as an anti DOI: 10.1117/12.2035591 -
Hydroxyl (O-H) confidence 1.0
“LLM confirmed rule peak-group candidate”
The Sustainability of Sweet Potato Residues from Starch Processing By-Products: Preparation with Lacticaseibacillus rhamnosus and Pediococcus pentosaceus, Characterization, and Application DOI: 10.3390/foods12010128 -
Hydroxyl (O-H) confidence 1.0
“CH2 Asymmetric stretching Polyvinyl chloride 2854 CH2 Symmetric stretching 3394 OH Stretching vibration (C═O), grafting polar group such as the carbonyl see According to Neagoe et al.”
Modification of surface characteristic and tribo-electric properties of polymers by DBD plasma in atmospheric air DOI: 10.1051/epjap/2017170149 -
confidence 1.0
“The absorption near 3394 cm-1 was detected in some samples, which was related to the N-H bond [39].”
Cai 等 - 2021 - Microdiamonds in Alkalic Dolerites from the North DOI: 10.3390/cryst11111325 -
confidence 1.0
“As for the DTAT and PETAT, N-H cm-1 cm-1 cm-1 cm-1 bands at 3394 and 3257 and C=N of triazine ring bands at 1425 and 1556 could Materials 2018, 11, 111”
The Effects of a Macromolecular Charring Agent with Gas Phase and Condense Phase Synergistic Flame Retardant Capability on the Properties of PP/IFR Composites DOI: 10.3390/ma11010111
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