What absorbs at 824 cm⁻¹ in an FTIR spectrum?
A band near 824 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 824 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.
Iespējamie funkcionālo grupu piešķīrumi
| Funkcionālā grupa | Atbalstošie fakti | Citētie avoti | Augstākā pārliecība |
|---|---|---|---|
| Alkyl C-H | 7 | 7 | 1,0 |
| Aromatic ring | 2 | 2 | 1,0 |
| Carbon dioxide | 1 | 1 | 1,0 |
| N h | 1 | 1 | 1,0 |
| Secondary amine | 1 | 1 | 1,0 |
| C n single bond | 1 | 1 | 1,0 |
| Amide | 1 | 1 | 1,0 |
| Nitro (NO2) | 1 | 1 | 1,0 |
| Alkene (C=C) | 1 | 1 | 1,0 |
| C-S single bond | 1 | 1 | 1,0 |
| C c single bond | 1 | 1 | 1,0 |
| Hydroxyl (O-H) | 1 | 1 | 1,0 |
| Siloxane (Si-O-Si) | 1 | 1 | 1,0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1,0 |
| Silicon (Si) | 1 | 1 | 1,0 |
| Oxygen heterocycle | 1 | 1 | 1,0 |
| C=n | 1 | 0 | 1,0 |
Rangs atspoguļo uzkrātos literatūras pierādījumus, nevis vienu autoritatīvu noteikumu. Vienmēr apstipriniet atbilstoši parauga kontekstam.
Possible materials
| Materiāls | Atbalstošie pīķi | Overlapping groups | Citētie avoti |
|---|---|---|---|
| polyurethane | 824, 2270, 1700 | Alkyl C-H, N h | 1 |
| saliva | 824, 1648, 1664 | Alkyl C-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 824 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.
Literatūra aiz šiem piešķīrumiem
-
Oxygen heterocycle pārliecība 1,0
“LLM confirmed rule peak-group candidate”
Mudri 等 - 2020 - Comparative Study of Aromatic and Cycloaliphatic I DOI: 10.3390/polym12071494 -
Silicon (Si) pārliecība 1,0
“ences corresponding increase in absorption peaks at 824 and 1055 In the mean time, a non-porous sample (c-Si) showed insignificant to the Si O Si vibration mode.”
A combination of electroless and electrochemical etching methods for enhancing the uniformity of porous silicon substrate for light detection application DOI: 10.1016/j.apsusc.2012.03.056 -
Alkyl C-H pārliecība 1,0
“C-H rocking of pure PVA is considered the cm-1 peak at 824 [31].”
From Green Remediation to Polymer Hybrid Fabrication with Improved Optical Band Gaps DOI: 10.3390/ijms20163910 -
pārliecība 1,0
“The peaks at 746 and 824 cm-1 in the UiO-66 framework, Zr-µ3-OH stretching and OH bending modes, respectively [46].”
Butova 等 - 2023 - In Situ FTIR Spectroscopy for Scanning Accessible DOI: 10.3390/nano13101675 -
C c single bond pārliecība 1,0
“In the spectra obtained after the cut-off at 3 kDa, the only signals related to proteins are the out-of-ring breathing of cm-1), cm-1), tyrosine (824 the C-C stretching of the proline ring (926 the C-C stretching cm-1),”
The Role of the Preanalytical Step for Human Saliva Analysis via Vibrational Spectroscopy DOI: 10.3390/metabo13030393 -
Alkyl C-H pārliecība 1,0
“In order to perform semi-quantitative analyses, the peaks were normalised cm-1 using the peak located at ~824 attributed to the C-H deformation of the PPTA sequence aging duration.”
Derombise 等 - 2009 - Degradation of Technora aramid fibres in alkaline DOI: 10.1016/j.polymdegradstab.2009.07.021 -
Alkyl C-H pārliecība 1,0
“Figure 4: FTIR spectrum of as-received Technora T240 fibres cm-1 The peaks were normalised using the peak located at ~824 attributed to the C-H deformation of”
Influence of finish treatment on the durability of aramid fibers aged under an alkaline environment DOI: 10.1002/app.31534 -
C-S single bond pārliecība 1,0
“The peak cm-1 824 is responsible for the C-S stretching vibrations at 7.35 ppm (peak j) is attributed to the protons at position of thiophene structures.”
Doan 等 - 2022 - Synthesis of Conjugated Molecules Based on Dithien DOI: 10.21577/0103-5053.20220031
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