What absorbs at 3437 cm⁻¹ in an FTIR spectrum?
A band near 3437 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 3437 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) | 14 | 13 | 1.0 |
| Water (H2O) | 5 | 5 | 1.0 |
| N h | 3 | 2 | 1.0 |
| C-O single bond | 2 | 2 | 1.0 |
| Alkyl C-H | 2 | 2 | 1.0 |
| Methacrylate | 2 | 2 | 1.0 |
| Acetate | 2 | 2 | 1.0 |
| Alkene (C=C) | 1 | 1 | 1.0 |
| Siloxane (Si-O-Si) | 1 | 1 | 1.0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1.0 |
| Silicon (Si) | 1 | 1 | 1.0 |
| Hydrogen bond | 1 | 1 | 1.0 |
| Methoxy (OCH3) | 1 | 1 | 1.0 |
| C c 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 |
| Amide | 1 | 1 | 1.0 |
| Secondary amine | 1 | 0 | 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 |
|---|---|---|---|
| ZnO | 3437, 1400, 3430 | Hydroxyl (O-H), C-O single bond | 1 |
| AgNPs | 3437, 1232, 1048 | N h, Hydroxyl (O-H), C-O single bond | 1 |
| polysaccharide | 3437, 1637, 1320 | Hydroxyl (O-H), C-O single bond, 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 3437 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
“LLM confirmed rule peak-group candidate”
Removal of hazardous pollutants from wastewater: Catalytic applications of Mg nanoparticle functionalized aminoclay DOI: 10.1016/j.molliq.2019.112005 -
Hydroxyl (O-H) confidence 1.0
“From Fig4000 3500 3000 2500 2000 1500 1000 500 3424cm-1 ure 1, the peaks are observed at 3437, 3414, and (cm-1 Wavelength ) corresponding to the O-H stretching mode of the hydroxyl amine group.”
Sanmugam 等 - 2017 - Optical and Structural Properties of Solvent Free DOI: 10.1155/2017/7536364 -
Water (H2O) confidence 1.0
“cm(cid:1)1wavenumbers 1458,1008, 540 and 468 The band at 3437 and 3445 could be assigned to stretching bonds of surface water molecules or to an envelope formed by hydrogen bonded surface OH groups [39].”
Role of iron in the enhanced reactivity of pulverized Red mud: Analysis by Mssbauer spectroscopy and FTIR spectroscopy DOI: 10.1016/j.cscm.2019.e00266 -
Hydroxyl (O-H) confidence 1.0
“cm(cid:1)l In the organic linings of calcareous foraminifera, a band in the region 3436.87 and cm(cid:1)l 3436.90 arises from the stretching vibration of a hydroxy group, H-bonded OH stretching was observed at both station 3 and 4.”
Sreenivasulu 等 - 2017 - Organic matter from benthic foraminifera (Ammonia DOI: 10.1016/j.mex.2017.01.001 -
Water (H2O) confidence 1.0
“with the presence of coordinated water, and with results reported for the analogous trans21 cm-1 cm-1 [Ru(NO)(H 2O)(NH 3) 4]Cl [58], bands at 3437 (broad, OH), 1622 (OH) and 22 3 cm-1 941 (weak, Ru-OH 2) were observed.”
de Souza Gois 等 - 2019 - A ruthenium nitrosyl cyclam complex with appended DOI: 10.1016/j.poly.2019.114117 -
Alkyl C-H confidence 1.0
“A broad peak at about 3437 cm-1 could be assigned to aliphatic C-H stretching (-OH) group.”
Microwave Accelerated Green Synthesis of Stable Silver Nanoparticles with Eucalyptus globulus Leaf Extract and Their Antibacterial and Antibiofilm Activity on Clinical Isolates DOI: 10.1371/journal.pone.0131178 -
Hydroxyl (O-H) confidence 1.0
“The FTIR reflectance spectra of pure diabetic mice given IP injections of KBA (Group 3) cm-1 KBA demonstrated characteristic peaks at 3437 showed a normal liver architecture (Figure-6a) with cm-1 (O-H stretching), 2932 (C-H stretching), 169”
Evaluation of the solubility of 11-keto-β-boswellic acid and its histological effect on the diabetic mice liver using a novel technique DOI: 10.14202/vetworld.2021.1797-1803 -
Hydroxyl (O-H) confidence 1.0
“Identification of Microorganism Bi in wavelengths of 583 cm-1, 737 cm-1 stretching Sixty-five isolated bacteria from hospitalized patients vibrational of O-Bi-O, and 1630 cm-1 stretching of Bi-O with burn infections was identified following”
Dalvand 等 - 2018 - Inhibitory Effect of Bismuth Oxide Nanoparticles P DOI: 10.21859/ijb.2102
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