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
Răspuns rapid
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.
Atribuiri posibile ale grupelor funcționale
| Grup funcțional | Fapte suport | Surse citate | Încredere maximă |
|---|---|---|---|
| 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 |
Clasamentul reflectă dovezile acumulate din literatură, nu o singură regulă autoritară. Confirmați întotdeauna în contextul mostrei dvs.
Materiale posibile
| Material | Vârfuri suport | Grupuri suprapuse | Surse citate |
|---|---|---|---|
| polyurethane | 824, 2270, 1700 | Alkyl C-H, N h | 1 |
| saliva | 824, 1648, 1664 | Alkyl C-H | 1 |
Materialele sunt afișate numai atunci când același grup de literatură susține această bandă și cel puțin un vârf caracteristic suplimentar.
Logica spectrului
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.
Utilizare în condiții reale
Acest tip de interogare este comun în identificarea polimerilor, screeningul materialelor plastice necunoscute, depanarea QC, verificarea materialelor reciclate și revizuirea atribuirii vârfurilor bazată pe literatură.
Greșeli comune
- Tratarea unei benzi izolate ca dovadă a unui material fără a verifica cel puțin unul sau două vârfuri de susținere.
- Ignorând suprapunerea: mai multe grupuri funcționale pot contribui în apropierea aceluiași număr de undă.
- Omiterea validării atunci când aditivii, amestecurile, oxidarea sau contaminarea pot distorsiona spectrul.
Sfat de verificare
Când ambiguitatea rămâne, validați ipoteza prin DSC, GC-MS sau TGA, în special pentru amestecuri, probe degradate și polimeri umpluți.
Literatura din spatele acestor atribuiri
-
Oxygen heterocycle încredere 1,0
“LLM confirmed rule peak-group candidate”
Mudri 等 - 2020 - Comparative Study of Aromatic and Cycloaliphatic I DOI: 10.3390/polym12071494 -
Silicon (Si) încredere 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 încredere 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 -
încredere 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 încredere 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 încredere 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 încredere 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 încredere 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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