What absorbs at 824 cm⁻¹ in an FTIR spectrum?
Una banda cerca de 824 cm⁻¹ puede apuntar a varios grupos funcionales. A continuación se muestran las asignaciones más probables, clasificadas por cuánta evidencia publicada respalda cada una — cada una trazable a literatura (DOI) y validada de forma cruzada con nuestros más de 130,000 espectros de referencia y grafo de conocimiento.
Backed by 8 cited sources
Respuesta rápida
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.
Posibles asignaciones de grupos funcionales
| Grupo funcional | Hechos de respaldo | Fuentes citadas | Confianza máxima |
|---|---|---|---|
| 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 |
La clasificación refleja la evidencia acumulada de la literatura, no una única regla autorizada. Siempre confirme según el contexto de su muestra.
Materiales posibles
| Material | Picos de apoyo | Grupos superpuestos | Fuentes citadas |
|---|---|---|---|
| polyurethane | 824, 2270, 1700 | Alkyl C-H, N h | 1 |
| saliva | 824, 1648, 1664 | Alkyl C-H | 1 |
Los materiales se muestran solo cuando el mismo grupo de literatura respalda esta banda y al menos un pico característico adicional.
Lógica de espectro
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.
Uso en el mundo real
Este tipo de consulta es común en la identificación de polímeros, cribado de plásticos desconocidos, resolución de problemas de control de calidad, verificación de materiales reciclados y revisión de asignación de picos respaldada por la literatura.
Errores comunes
- Tratar una banda aislada como prueba de un material sin verificar al menos uno o dos picos de apoyo.
- Ignorando superposición: múltiples grupos funcionales pueden contribuir cerca del mismo número de onda.
- Omitir la validación cuando los aditivos, las mezclas, la oxidación o la contaminación puedan distorsionar el espectro.
Consejo de verificación
Cuando persista la ambigüedad, valide la hipótesis con DSC, GC-MS o TGA, especialmente para mezclas, muestras degradadas y polímeros rellenos.
Literatura detrás de estas asignaciones
-
Oxygen heterocycle confianza 1,0
“LLM confirmed rule peak-group candidate”
Mudri 等 - 2020 - Comparative Study of Aromatic and Cycloaliphatic I DOI: 10.3390/polym12071494 -
Silicon (Si) confianza 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 confianza 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 -
confianza 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 confianza 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 confianza 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 confianza 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 confianza 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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