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
Snabbt svar
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.
Möjliga identifieringar av funktionella grupper
| Funktionell grupp | Stödjande fakta | Citerade källor | Högsta förtroende |
|---|---|---|---|
| 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 |
Rankingen speglar ackumulerade litteraturbevis, inte en enda auktoritativ regel. Bekräfta alltid mot din provkontext.
Möjliga material
| Material | Stödjande toppar | Överlappande grupper | Citerade källor |
|---|---|---|---|
| ZnO | 731, 1400, 3430 | Acetate, Methacrylate, C-O single bond | 1 |
| ZnO nanoparticles | 731, 1219, 1726 | Methacrylate, Acetate, C-O single bond | 1 |
Material visas endast när samma litteraturpool stöder detta band och minst en ytterligare karakteristisk topp.
Spektrumlogik
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.
Användning i verkligheten
Denna typ av fråga är vanlig inom polymeridentifiering, screening av okänd plast, felsökning av kvalitetskontroll, verifiering av återvunnet material och litteraturstödd toppidentifieringsgranskning.
Vanliga misstag
- Behandla ett isolerat band som bevis på ett material utan att kontrollera minst en eller två stödjande toppar.
- Ignorerar överlapp: flera funktionella grupper kan bidra nära samma vågtal.
- Hoppa över validering när tillsatser, blandningar, oxidation eller föroreningar kan förvränga spektrat.
Verifieringsråd
När oklarhet kvarstår, validera hypotesen med DSC, GC-MS eller TGA, särskilt för blandningar, nedbrutna prover och fyllda polymerer.
Litteratur bakom dessa identifieringar
-
Hydroxyl (O-H) förtroende 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 -
förtroende 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 -
förtroende 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) förtroende 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 förtroende 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
Har du ett spektrum med detta band?
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