What absorbs at 3446 cm⁻¹ in an FTIR spectrum?
A band near 3446 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 3446 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) | 17 | 17 | 1.0 |
| N h | 6 | 6 | 1.0 |
| Water (H2O) | 4 | 4 | 1.0 |
| Methacrylate | 2 | 2 | 1.0 |
| Acetate | 2 | 2 | 1.0 |
| Amide | 2 | 2 | 1.0 |
| Carbohydrate | 2 | 1 | 1.0 |
| Methoxy (OCH3) | 1 | 1 | 1.0 |
| C-O single bond | 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 |
| Amine primary | 1 | 1 | 1.0 |
| Metal hydroxyl | 1 | 1 | 1.0 |
| Metal oxygen | 1 | 1 | 1.0 |
| Alkyl C-H | 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 |
|---|---|---|---|
| NiO | 3446, 1006, 1450 | Hydroxyl (O-H), N h, Methacrylate | 1 |
| silver nanoparticles | 3446, 1636, 1631 | Hydroxyl (O-H), Methacrylate, N h | 1 |
| ZnO | 3446, 1400, 3430 | Hydroxyl (O-H), Methacrylate | 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 3446 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
“cm(cid:3)1 The vibrational peak at 3446 1108, 2087 and 3446 Overall reaction corresponds to O-H stretching.”
Synthesis and Characterization of Silicon Nanowires by Electroless Etching DOI: 10.1007/s11665-018-3179-z -
Hydroxyl (O-H) confidence 1.0
“cm-1 of A prominent hump at 3446.09 due to hydroxyl ( OH stretch) is observed for [University 400◦C.”
Datta 和 Agrawal - 2005 - Effect of acetylacetone on the phase formation of DOI: 10.1080/00150190500308611 -
confidence 1.0
“The cm-1 absorbance peaks at 3446 can be assigned to N-H stretching vibrations present in the amide linkages of primary and secondary amines of proteins [25] and O-H stretching vibrations of cm-1 phenols/alcohols [26].”
Hieu 等 - 2022 - Microorganism-mediated green synthesis of silver n DOI: 10.15251/DJNB.2022.171.359 -
Hydroxyl (O-H) confidence 1.0
“12 13 cm-1 observed peak at 3446 may be due to absorption of hydroxyl group which observed in 14 15 cm-1 DZ1 sample.”
Najafidoust 等 - 2019 - The role of Diethanolamine as stabilizer in contro DOI: 10.1088/2053-1591/ab2a43 -
confidence 1.0
“3650-3250cm-1 cm-1 cm-1 cm-1 1010.16 and 922.53 ±1050 (Medium) -COOH (C-O Stretching) -NH2 (N-HStretching) (Medium) 1638.22cm-1 1650-1590cm-1 -NH2 (N-HBending) (Medium) cm-1 cm-1 3650-3250 (Medium) -NH2 (N-H Stretching) 3445.97 1030.64cm-1”
Validation of the Developed Zero-Order Infrared Spectrophotometry Method for Qualitative and Quantitative Analyses of Tranexamic Acid in Marketed Tablets DOI: 10.3390/molecules26226985 -
Hydroxyl (O-H) confidence 1.0
“LLM confirmed rule peak-group candidate”
Investigation of structural and optical properties of NiO nanoparticles mediated by Plectranthus amboinicus leaf extract DOI: 10.1016/j.matpr.2020.03.581 -
Hydroxyl (O-H) confidence 1.0
“LLM confirmed rule peak-group candidate”
Sakthisharmila 等 - 2017 - A characteristic study on generation and interacti DOI: 10.1016/j.molliq.2017.01.106 -
Water (H2O) confidence 1.0
“The IR region cm-1 at 3446 consists of vibrations due to water, hydroxyl or similar groups [36].”
Study on the Overall Reaction Pathways and Structural Transformations during Decomposition of Coal Fly Ash in the Process of Alkali-Calcination DOI: 10.3390/ma14051163
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