What absorbs at 3629 cm⁻¹ in an FTIR spectrum?
A band near 3629 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 5 cited sources
Quick answer
A band near 3629 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.
Attributions possibles de groupes fonctionnels
| Groupe fonctionnel | Faits à l＇appui | Sources citées | Confiance maximale |
|---|---|---|---|
| Hydroxyl (O-H) | 2 | 2 | 1,0 |
| Hydrogen bond | 1 | 1 | 1,0 |
| N h | 1 | 1 | 1,0 |
| Carbonate | 1 | 1 | 1,0 |
| Silicate | 1 | 1 | 0,9 |
Le classement reflète les preuves bibliographiques accumulées, et non une règle faisant autorité. Confirmez toujours dans le contexte de votre échantillon.
Possible materials
| Matériel | Pics de support | Overlapping groups | Sources citées |
|---|---|---|---|
| clay | 3629, 1736, 2855 | Hydroxyl (O-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 3629 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.
Bibliographie derrière ces attributions
-
Hydroxyl (O-H) confiance 1,0
“Queralt [40] reported that hydrated cm-1 calcium-magnesium carbonates show a broadband centered around 3435 and a cm-1, cm-1 sharp band at 3629 thus the broad shoulder at 3487 could be assigned to both hydroxyl stretching modes of hydrated”
The Physico-Chemical and Mineralogical Characterization of Mg-Rich Synthetic Gypsum Produced in a Rare Earth Refining Plant DOI: 10.3390/su13094840 -
Hydroxyl (O-H) confiance 1,0
“LLM confirmed rule peak-group candidate”
Boron Removal by Adsorption on Cobalt(II) Doped Chitosan Bio-composite DOI: 10.1007/s10924-017-1099-x -
confiance 0,95
“Explicit assignment: 'at 3629 in Ni smectite precursor ... is assigned vNi3OH'”
The crystal growth of smectite: A study based on the change in crystal-chemistry and morphology of saponites with synthesis time DOI: 10.1021/ac -
confiance 0,9
“Band centered at ~3629 assigned to Al3+Al3+□-OH- arrangements.”
Tobelite and NH4+-rich muscovite single crystals from Ordovician Armorican sandstones (Brittany, France): Structure and crystal chemistry DOI: 10.2138/am.2012.4023 -
Silicate confiance 0,9
“absorption bands at 3629 refer to stretching vibration of silicates”
Enhanced Coating Protection of C-Steel Using Polystyrene Clay Nanocomposite Impregnated with Inhibitors DOI: 10.3390/polym15020372
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