What absorbs at 3422 cm⁻¹ in an FTIR spectrum?
A band near 3422 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 3422 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) | 20 | 19 | 1.0 |
| N h | 6 | 6 | 1.0 |
| Alkyl C-H | 2 | 2 | 1.0 |
| Carboxyl (COOH) | 2 | 2 | 1.0 |
| Water (H2O) | 2 | 1 | 1.0 |
| Amide | 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 |
| Methyl | 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 |
|---|---|---|---|
| silver nanoparticles | 3422, 1636, 1631 | Hydroxyl (O-H), Alkyl C-H, N h | 2 |
| iron oxide | 3422, 1130, 891 | Alkyl C-H, Hydroxyl (O-H) | 1 |
| montmorillonite | 3422, 1637, 523 | Hydroxyl (O-H), Carboxyl (COOH) | 1 |
| bentonite | 3422, 882, 918 | Hydroxyl (O-H) | 1 |
| gold nanoparticles | 3422, 1638, 3252 | Alkyl C-H, Hydroxyl (O-H) | 1 |
| iron oxide nanoparticles | 3422, 2972, 528 | Hydroxyl (O-H), Alkyl C-H, Carboxyl (COOH) | 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 3422 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
-
Carboxyl (COOH) confidence 1.0
“Additionally, peaks were found In the case of Riva Light Cure, an initial band was found at 3422 cm-1, indicative of cm-1, COO-, cm-1, near 1636 corresponding to followed by a peak at 1419 corresponding the presence of OH groups.”
Remineralization Potential of Three Restorative Glass Ionomer Cements: An In Vitro Study DOI: 10.3390/jcm12062434 -
Hydroxyl (O-H) confidence 1.0
“Furthermore, have no significant changes, showing stretch vithe quartz minerals were detected at 26°, then feldcm-1 bration of the interlayer O-H group at 3422 cm-1 and 1635 (Wei et al., 2020).”
Hakim 等 - 2023 - Ammonium-Assisted Intercalation of Java Bentonite DOI: 10.12911/22998993/156665 -
Hydroxyl (O-H) confidence 1.0
“-OH stretching, hydration - - 3422 -OH stretching, hydration 3420”
Hayati-Ashtiani - 2012 - Use of FTIR Spectroscopy in the Characterization o DOI: 10.1080/02726351.2011.615895 -
Hydroxyl (O-H) confidence 1.0
“The bands at 3422 1630 arise due to O-H stretching vibration of surface-adsorbed water molecules [30].”
Karpagavinayagam 和 Vedhi - 2019 - Green synthesis of iron oxide nanoparticles using DOI: 10.1016/j.vacuum.2018.11.043 -
Hydroxyl (O-H) confidence 1.0
“which is due to the O-H sorption bands at 3422 52 K.M.”
Parida 等 - 2004 - Studies on manganese-nodule leached residues - 1. DOI: 10.1016/j.jcis.2004.04.057 -
Hydroxyl (O-H) confidence 1.0
“have caused the O-H-extending vibration peak at 3422 The phytochemical's presence”
Biosynthesis and Characterization of Silver Nanoparticles Using Tribulus terrestris Seeds: Revealed Promising Antidiabetic Potentials DOI: 10.3390/molecules28104203 -
confidence 1.0
“The FTIR spectrum of pure CTX (Figure 5A) shows a characteristic absorption cm-1, band at 3422.18 corresponding to N-H and O-H groups (stretching vibrations).”
Cefotaxime Mediated Synthesis of Gold Nanoparticles: Characterization and Antibacterial Activity DOI: 10.3390/polym14040771 -
Carboxyl (COOH) confidence 1.0
“flexuosus NPs of and reported bands at 3422 due to the carboxyl group, 2170 cm-1”
Biological Activity of Biosynthesized Silver Nanoaggregates Prepared from the Aqueous Extract of Cymbopogon citratus against Candida spp. DOI: 10.3390/nano13152198
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.