What absorbs at 3322 cm⁻¹ in an FTIR spectrum?
A band near 3322 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 3322 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) | 4 | 4 | 1.0 |
| Alkyl C-H | 2 | 2 | 1.0 |
| Carbohydrate | 2 | 2 | 1.0 |
| Metal oxygen | 1 | 1 | 1.0 |
| Nitride | 1 | 1 | 1.0 |
| Carbonyl (C=O) | 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 |
|---|---|---|---|
| polyurethane | 3322, 2270, 1700 | Alkyl C-H | 2 |
| PVA | 3322, 1660, 2930 | Alkyl C-H, Hydroxyl (O-H) | 1 |
| Cellulose | 3322, 1735, 1650 | Alkyl C-H, Hydroxyl (O-H), Carbohydrate | 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 3322 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
“A peak at cm-1 3074 belonged to weak O-H stretching [30] and cm-1 a broad peak at 3322 was attributed to O-H”
Influence of Ho3+ substitution on structural and magnetic properties of Mg–Mn ferrites DOI: 10.1007/s10854-021-05547-9 -
Carbohydrate confidence 1.0
“Samples (cm-1) (cm-1) (cm-1) MS cellulose CMC assignment -OH 3322 3322 3322 stretching -CH 2900 2900 2900 stretching -CO 1588 stretching”
Akhlaq 和 Uroos - 2023 - Evaluating the Impact of Cellulose Extraction via DOI: 10.1021/acsomega.2c08118 -
Hydroxyl (O-H) confidence 1.0
“LLM confirmed rule peak-group candidate”
Aziz 等 - 2019 - Structural and Optical Characteristics of PVAC-Do DOI: 10.3390/nano9020216 -
Hydroxyl (O-H) confidence 1.0
“intensity of peak reached the maximum when the position was 2894 The bands at cm-1 3322 and 2894 are assigned as -OH stretching vibration and -CH stretching in cellulose-II, respectively (Yukako et al.”
Bian 等 - 2021 - Crystalline Structure Analysis of All-cellulose Na DOI: 10.1007/s10570-017-1259-0 -
Alkyl C-H confidence 1.0
“cm-1, the C-H stretching vibration at 2942 cm-1, C-H bending vibrations at 1428 cm-1, and cm-1, cm-1, cm-1, 3322 the C-H stretching vibration at 2942 C-H bending vibrations at 1428 C-O-C stretching vibrations at 1049 cm-1, 988 cm-1, and 908”
Structural Analysis of Oxidized Sucrose and Its Application as a Crease-Resistant Crosslinking Agent DOI: 10.3390/polym14142842 -
Amide confidence 1.0
“Materials 2023, 16, x FOR PEER REVIEW 11 of 14 cm-1 change in intensity (increase for band at 1728 and decrease for bands at 1686, 3322 cm-1) and 1531 and shift of absorption bands of amide and carbonyl groups (Figure 5a,d).”
The Influence of Long-Time Storage on the Structure and Properties of Multi-Block Thermoplastic Polyurethanes Based on Poly(butylene adipate) Diol and Polycaprolactone Diol DOI: 10.3390/ma16020818 -
Hydroxyl (O-H) confidence 1.0
“and amine group at 3322 cm-1 The FTIR spectrum of the coating agent made from PU (100% PU) showed the characteristic ν(OH) The broad and strong peak ranging from 3200 to 3300 and assigned to groups showed cm-1, peaks of PU, such as peaks of”
Rogina-Car 等 - 2020 - Influence of Washing and Sterilization on Properti DOI: 10.3390/polym12030642 -
Nitride confidence 1.0
“Strong peaks appeared at 1621 and 3322 cm-1, showing conjugation between graphitic carbon nitride and metal oxide, as in previous spectra.”
Electro-Oxidation of Metal Oxide-Fabricated Graphitic Carbon Nitride for Hydrogen Production via Water Splitting DOI: 10.3390/coatings12050548
Have a spectrum with this band?
Upload your FTIR spectrum and get a full interpretation report — peak assignments with literature citations, library matches, and a literature-backed analysis — in seconds.