What absorbs at 819 cm⁻¹ in an FTIR spectrum?
A band near 819 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 6 cited sources
Quick answer
A band near 819 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.
可能的官能团归属
| 官能团 | 支持性事实 | 引用来源 | 最高置信度 |
|---|---|---|---|
| Aromatic ring | 3 | 2 | 1.0 |
| Alkyl C-H | 2 | 1 | 1.0 |
| Silicon carbon | 1 | 1 | 1.0 |
| Methoxy (OCH3) | 1 | 1 | 1.0 |
| Methacrylate | 1 | 1 | 1.0 |
| C-O single bond | 1 | 1 | 1.0 |
| Acetate | 1 | 1 | 1.0 |
| Chlorine | 1 | 1 | 1.0 |
排名反映了累积的文献证据，而非单一的权威规则。请始终对照您的样品背景进行确认。
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 819 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.
这些分配背后的文献
-
置信度 1.0
“Additionally, the peak observed at 819 shows the presence of C-Cl bond.”
Quaternarization and polymerization of 2-chloroethyl maleate derivative of epoxidized soybean oil DOI: 10.55730/1300-0527.3503 -
Alkyl C-H 置信度 1.0
“The absorption bands at 2924 and 1499 were generated by stretching of C-H and C=C cm-1 in the benzene ring, respectively, whereas the band at 819 was due to the symmetrical elongation of”
Preparation and Evaluation of a Polyimide-Coated Ultrafine Gilt Molybdenum Wire and Its Knitted Mesh Used for Electromagnetic Reflectors DOI: 10.3390/polym9120734 -
Acetate 置信度 1.0
“cm-1 C-O stretching, while the peak at ~819 can be attributed to C-O-C in plan symmetric bending [55-58].”
Excellent Fire Retardant Properties of CNF/VMT Based LBL Coatings Deposited on Polypropylene and Wood-Ply DOI: 10.3390/polym13020303 -
Silicon carbon 置信度 1.0
“LLM confirmed rule peak-group candidate”
Wang 等 - 2015 - A facile method to fabricate Al4B2O9 whiskers on p DOI: 10.1007/s40145-015-0154-0 -
Aromatic ring 置信度 0.95
“Text: 'the out-of-plane bending of the benzene ring (819 cm-1)'”
Jevremovic 等 - 2014 - Investigation of the effect of acid dopant on the DOI: 10.1016/j.cap.2014.06.018 -
置信度 0.9
“Text states: 'peak at 819 cm-1 was attributed to a plasmon related peak'.”
Optical properties of InAs/InP quantum dot stack grown by metalorganic chemical vapor deposition DOI: 10.1002/pssc.200303088
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