What absorbs at 731 cm⁻¹ in an FTIR spectrum?
A band near 731 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 731 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.
可能性のある官能基アサイン
| 官能基 | 裏付け事実 | 引用元 | 最高信頼度 |
|---|---|---|---|
| Methoxy (OCH3) | 1 | 1 | 1.0 |
| Methacrylate | 1 | 1 | 1.0 |
| C-O single bond | 1 | 1 | 1.0 |
| Acetate | 1 | 1 | 1.0 |
| Alkyl C-H | 1 | 1 | 1.0 |
| Water (H2O) | 1 | 1 | 1.0 |
| Chlorine | 1 | 1 | 1.0 |
| Fluorine (C-F) | 1 | 1 | 1.0 |
| Hydroxyl (O-H) | 1 | 1 | 1.0 |
ランキングは蓄積された文献証拠を反映しており、単一の権威あるルールではありません。常にサンプルのコンテキストと照合して確認してください。
Possible materials
| 素材 | 補助ピーク | Overlapping groups | 引用元 |
|---|---|---|---|
| ZnO | 731, 1400, 3430 | Acetate, Methacrylate, C-O single bond | 1 |
| ZnO nanoparticles | 731, 1219, 1726 | Methacrylate, Acetate, C-O single bond | 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 731 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.
これらのアサインの根拠となる文献
-
Hydroxyl (O-H) 信頼度 1.0
“Unassociated hydroxyl peaks at 731 and 653 in Raman occurred in the compound”
Arjunan 等 - 2012 - Quantum chemical studies and vibrational analysis DOI: 10.1016/j.saa.2012.08.053 -
信頼度 1.0
“cm-1 Peaks below 900 are not usually interpreted because they represent too complex a 6 cm-1 structural signature, but the presence of a sharp and strong peak at 731 can be assigned to the presence of stretching mode of C-F bonds [28].”
Algarra 等 - 2018 - Enhanced electrochemical response of carbon quantu DOI: 10.1016/j.talanta.2017.09.082 -
信頼度 1.0
“chainsinparallelorperpendicularlytotheplaneofthechains[23].The 731cm-1 C-Cl peak at was found to emanate from the rocking of the (0%100%), targetingbothattheextremevaluesandalsotodetect,with bonds [56].”
Giannoukos 和 Salonitis - 2020 - Study of the mechanism of friction on functionally DOI: 10.1016/j.triboint.2019.105906 -
Water (H2O) 信頼度 1.0
“The peaks at 731 650 1388 cm-1 are due to vibrations of free water molecules.”
Investigation of morphological, structural and electronic transformation of PVDF and ZnO/rGO/PVDF hybrid membranes DOI: 10.1007/s11082-023-04663-6 -
Acetate 信頼度 1.0
“A intense band at about 1300-1000 dine-like structure (m2/g) BET surface area A 685 630 697 731 cm-1 corresponds to the stretching in C-O, C-O-C, O-H in Average pore width d (nm) 3.13 2.73 3.18 2.43 carboxylic acids, anhydrides, lactones, e”
Yang JiLiang 等 - 2013 - Effect of microstructure and surface chemistry in DOI: 10.1007/s11434-013-6040-7
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