What absorbs at 823 cm⁻¹ in an FTIR spectrum?
A band near 823 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 823 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 |
|---|---|---|---|
| Hydroxyl (O-H) | 4 | 4 | 1,0 |
| Aromatic ring | 4 | 4 | 1,0 |
| Ring structure | 3 | 3 | 1,0 |
| Alkyl C-H | 3 | 3 | 1,0 |
| C c single bond | 2 | 2 | 1,0 |
| Siloxane (Si-O-Si) | 1 | 1 | 1,0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1,0 |
| Silicon (Si) | 1 | 1 | 1,0 |
| Metal oxygen | 1 | 1 | 1,0 |
| N h | 1 | 1 | 1,0 |
| Oxygen heterocycle | 1 | 1 | 1,0 |
| Alkene (C=C) | 1 | 1 | 1,0 |
Rankingen speglar ackumulerade litteraturbevis, inte en enda auktoritativ regel. Bekräfta alltid mot din provkontext.
Possible materials
| Material | Stödjande toppar | Overlapping groups | Citerade källor |
|---|---|---|---|
| pMMA | 823, 1722, 1383 | Alkyl C-H | 1 |
| ZnO | 823, 1400, 3430 | Hydroxyl (O-H), Alkyl C-H | 1 |
| PANI | 823, 2930, 1300 | Aromatic ring, Alkyl C-H, Ring structure | 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 823 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.
Litteratur bakom dessa identifieringar
-
Aromatic ring förtroende 1,0
“The benzene ring's =C-H bending vibration absorption peaks and benzene ring framework 886cm-1, 823cm-1 801cm-1.”
Li 等 - 2011 - The detection of Cypermethrin on the surface of Ap DOI: 10.4028/www.scientific.net/AMR.287-290.2991 -
Aromatic ring förtroende 1,0
“combination band at 823 of benzene ring rocking (H-C-C-C-H), symmetrical stretching of thiophene ring s(C-S-C) cm-1 and carbon-chloride stretching (C-Cl);”
Aguilar-Rodriguez 等 - 2023 - Microanalytical Characterization of an Innovative DOI: 10.3390/molecules28020564 -
Oxygen heterocycle förtroende 1,0
“LLM confirmed rule peak-group candidate”
Bio-Based Coating Materials Derived from Acetoacetylated Soybean Oil and Aromatic Dicarboxaldehydes DOI: 10.3390/polym11111809 -
förtroende 1,0
“C 15-H coupled to the N-H wag at 1348 The corresponding out-of-phase vibrations are r ip cm-1 at 823 and 868 for the C 7-H/C 8-H and C 11-H/C 12-H, while the bands for the C 14-H t and C 10-H wags, which are separated from a neighboring C-H”
Dioumaev 等 - 2010 - Low-Temperature FTIR Study of Multiple K Intermedi DOI: 10.1021/jp908698f. -
Metal oxygen förtroende 1,0
“3 cm-1 and the distinctive bands at 823 932, 823 and 761 cm-1 and 761 are recognized as the W-O-W stretching [41].”
He 等 - 2020 - Flexible fabric gas sensors based on PANIWO(3)p-n DOI: 10.1007/s40843-020-1364-4 -
Hydroxyl (O-H) förtroende 1,0
“presented in Figure 1d (spectra of other samples are available in Figure S2 in Supplementary Materials), cm-1 which shows a band at 823 due to hydrogen-bonded O-H stretch.”
Khalaf 等 - 2019 - Experimental Design Modeling of the Effect of Hexa DOI: 10.3390/molecules24213884 -
Aromatic ring förtroende 1,0
“The presence of the vibration at 823 in the porosity parameters of P4VPD used in sorption tests, spectrum is attributed to disubstituted aromatic rings obtained by nitrogen physisorption and mercury”
Maksin 等 - 2012 - Kinetic modeling of heavy metal sorption by vinyl DOI: 10.2298/HEMIND121002112M -
Hydroxyl (O-H) förtroende 1,0
“A predominant band between 3400 and 3700 corresponds to -OH anion in the interlaminar layer, while other bands at 625 and 823 cm-1 are related to vibrational modes stretching vibrations of the hydroxyl groups and water molecules found in th”
Nope 等 - 2020 - Ternary Hydrotalcites in the Multicomponent Synthe DOI: 10.3390/catal10010070
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