What absorbs at 3352 cm⁻¹ in an FTIR spectrum?
A band near 3352 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 3352 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) | 10 | 10 | 1.0 |
| N h | 5 | 5 | 1.0 |
| Alkyl C-H | 2 | 2 | 1.0 |
| Secondary amine | 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 |
| Water (H2O) | 1 | 1 | 1.0 |
| Hydrogen bond | 1 | 1 | 1.0 |
| Carbohydrate | 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 |
|---|---|---|---|
| chitosan | 3352, 1650, 1655 | Alkyl C-H, Hydroxyl (O-H), N h | 2 |
| Cellulose | 3352, 1735, 1650 | Alkyl C-H, Hydroxyl (O-H) | 2 |
| alginate | 3352, 1100, 1715 | Alkyl C-H, Hydroxyl (O-H) | 1 |
| silver nanoparticles | 3352, 1636, 1631 | Hydroxyl (O-H), Alkyl C-H, N h | 1 |
| sodium alginate | 3352, 1636, 1080 | Hydroxyl (O-H), Alkyl C-H | 1 |
| Silica | 3352, 1100, 1080 | Hydroxyl (O-H), Alkyl C-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 3352 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
“The FTIR spectra of hydrogen-bonded OH stretching vibrations at around 3352 were resolved into three bands for cellulose I and four bands for cellulose II, assuming that all the vibration modes follow Gaussian distribution.”
Oh 等 - 2005 - Crystalline structure analysis of cellulose treate DOI: 10.1016/j.carres.2005.08.007 -
Hydrogen bond confidence 1.0
“LLM confirmed rule peak-group candidate”
Xiao 等 - 2020 - Preparation and characterization of broken-rice st DOI: 10.1016/j.ijbiomac.2020.05.182 -
Hydroxyl (O-H) confidence 1.0
“LLM confirmed rule peak-group candidate”
Bacterial nanocellulose from agro-industrial wastes: low-cost and enhanced production by Komagataeibacter saccharivorans MD1 DOI: 10.1038/s41598-020-60315-9 -
Hydroxyl (O-H) confidence 1.0
“and3796cm-1and OH/Na-vibration,thebandsat3579.1to3580.5cm-1,3395.2 possiblethatthe bandsappearedat3730 3415.4cm-1, 3354.4cm-1 in this region may be resulted due to the presence of Feto and 3351.5 to are probably OH-vibration.”
Ahmad 等 - 2021 - Spectroscopic Analysis for Harnessing the Quality DOI: 10.1155/2021/6629640 -
Hydroxyl (O-H) confidence 1.0
“alginatecapped Ag-NPs, a more intense hydroxyl peak is visible around 3352 Since Ag-NPs are in the colloidal form with water as a component, this result is justified.”
Bhagyaraj 和 Krupa - 2020 - Alginate-Mediated Synthesis of Hetero-Shaped Silve DOI: 10.3390/molecules25030435 -
confidence 1.0
“92 and 89% efficiency of selenium entrapment in In the spectra of chitosan, the broad band at 3352 is alginate and alginate/chitosan microspheres was calculated based assigned to the amine and hydroxyl groups (O-H stretching), 2880 on UV/vi”
Preparation, structural characterisation and release study of novel hybrid microspheres entrapping nanoselenium, produced by green synthesis DOI: 10.1049/iet-nbt.2016.0107 -
Hydroxyl (O-H) confidence 1.0
“LLM confirmed rule peak-group candidate”
Fernandes 等 - 2011 - Cytocompatibility of Chitosan and Collagen-Chitosa DOI: 10.1590/S0104-14282011005000008 -
Hydroxyl (O-H) confidence 1.0
“Finally, lignin decomposition continues up to hydrogen-bonded OH stretching was shifted from 3352 to cm-1”
Marin 等 - 2015 - Revalorization of Rice Husk Waste as a Source of C DOI: 10.1007/s12221-015-0285-5
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