What absorbs at 3317 cm⁻¹ in an FTIR spectrum?
A band near 3317 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 3317 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 |
|---|---|---|---|
| N h | 7 | 6 | 1.0 |
| Hydroxyl (O-H) | 5 | 5 | 1.0 |
| Secondary amine | 3 | 3 | 1.0 |
| Urethane | 2 | 2 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Chlorine | 1 | 1 | 1.0 |
| Methoxy (OCH3) | 1 | 1 | 1.0 |
| C-O single bond | 1 | 1 | 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 |
| Alkyl C-H | 1 | 1 | 1.0 |
| N c o | 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 | 3317, 1650, 1540 | Hydroxyl (O-H) | 1 |
| Polyurethane | 3317, 2270, 1700 | N h | 1 |
| TiO2 | 3317, 1700, 1093 | Hydroxyl (O-H) | 1 |
| Al2O3 | 3317, 1722, 1383 | Hydroxyl (O-H) | 1 |
| rGO | 3317, 2358, 2930 | Hydroxyl (O-H), N h | 1 |
| hydrogels | 3317, 3281, 1700 | 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 3317 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
-
confidence 1.0
“and disappearance NCO peak at 2262 A rubber polyol as soft phase contributes FTIR with a N-H peak at 3317 a major implication in the polymer products and two-shot reaction was performed as better processable technique.”
Preparation of one-shot and two-shot method of semi-rigid polyurethane film based on functionalized liquid natural rubber DOI: 10.1063/1.5047200 -
N c o confidence 1.0
“peak at 3317 and disappearance of the NCO peak at 2295 The semirigid PU with low rubber polyol chain favored solubility in non-polar solvent (toluene and chloroform) and low polar solvent (THF).”
The behavior of semi-rigid polyurethane film based on functionalized rubber by one-shot and two-shot method preparation DOI: 10.1007/s10853-018-2578-8 -
Hydroxyl (O-H) confidence 1.0
“For as composite powders, the peaks around 3317 and cm-1 1630 corresponds to the O-H stretching and bending vibrations.”
Structural, optical, morphological and thermal properties of TiO2–Al and TiO2–Al2O3 composite powders by ball milling DOI: 10.1016/j.physleta.2017.02.053 -
Hydroxyl (O-H) confidence 1.0
“LLM confirmed rule peak-group candidate”
Owonubi 等 - 2018 - Characterization and in vitro release kinetics of DOI: 10.1007/s40090-018-0139-2 -
confidence 1.0
“The bands at 3317, 3412, 3440 cm-1 and 3464 correspond to the symmetric and asymmetric N-H stretching bands which cm-1 are observed at 3329 and 3428 in pristine urea (Yue, Jia et al.”
Ternary Natural Deep Eutectic Solvent (NADES) Infused Phthaloyl Starch as Cost Efficient Quasi-Solid Gel Polymer Electrolyte DOI: 10.1016/j.carbpol.2017.03.023 -
N h confidence 1.0
“The FTIR spectra (Figure 1) of DC confirmed the existence of cm-1 due to NH stretching, peaks at 3317, 1677, 1120, and 745 C=O stretching, C-O bending, and C-Cl bending as characteristic functional groups of DC.”
Battu 等 - 2018 - Biopharmaceutical Process of Diclofenac Multi-part DOI: 10.4274/tjps.92400 -
Hydroxyl (O-H) confidence 1.0
“The absorption peak at 3317 is due to the hydroxyl of”
Hu 等 - 2021 - Pyrolytic Characteristics and Kinetics of Guanzhon DOI: 10.1016/j.fuel.2014.01.014 -
confidence 1.0
“After 2 months of aging, the H-bonded cm´1 H-bonded N-H band of the sample exposed to 80% RH shifts to 3317 at the expense of free N-H band of the sample exposed to 80% RH shifts to 3317 cm-1 at the expense of free N-H band N-H band (Figure”
Microstructure Changes in Polyester Polyurethane upon Thermal and Humid Aging DOI: 10.3390/polym8050197
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