What absorbs at 856 cm⁻¹ in an FTIR spectrum?
Una banda cerca de 856 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 856 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 | 3 | 3 | 1,0 |
| Methacrylate | 3 | 3 | 1,0 |
| Acetate | 3 | 3 | 1,0 |
| Methoxy (OCH3) | 2 | 2 | 1,0 |
| C-O single bond | 2 | 2 | 1,0 |
| Hydroxyl (O-H) | 2 | 1 | 1,0 |
| Carbohydrate | 1 | 1 | 1,0 |
| Ketone | 1 | 1 | 1,0 |
| Ester | 1 | 1 | 1,0 |
| Carboxyl (COOH) | 1 | 1 | 1,0 |
| Carbonyl (C=O) | 1 | 1 | 1,0 |
| Amide | 1 | 1 | 1,0 |
| Carbonate | 1 | 1 | 1,0 |
| Oxygen heterocycle | 1 | 1 | 1,0 |
| C c single bond | 1 | 1 | 1,0 |
| Lignin | 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 |
|---|---|---|---|
| PVA | 856, 1660, 2930 | Alkyl C-H, Acetate, Methacrylate | 1 |
| MWCNT | 856, 2876, 1430 | Alkyl C-H, Methoxy (OCH3), Methacrylate | 1 |
| Cellulose | 856, 1735, 1650 | Alkyl C-H, Acetate, Methacrylate | 1 |
| lignin | 856, 1035, 1510 | Alkyl C-H, Methacrylate, Acetate | 1 |
| poly(vinyl alcohol) | 856, 1700, 2993 | Acetate, Methacrylate, Alkyl C-H | 1 |
| CeO2 | 856, 1554, 1630 | Acetate, Methacrylate, Methoxy (OCH3) | 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 856 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
-
C c single bond confianza 1,0
“4 (a)] showed features spectrum band at 2946.67 1 cm-1 (stretching vibration of C-H from alkyl group), 1142.72 ( C-O stretching vibration, 1436.69 cm-1 cm-1 cm-1 (-CH 2stretching), 855.72 (C-C stretching) and the absorption band at 3631.72”
Sprayed in-situ synthesis of Polyvinyl alcohol/Chitosan loaded Silver nanocomposite hydrogel for improved antibacterial effects DOI: 10.1016/j.ijbiomac.2019.09.186 -
Oxygen heterocycle confianza 1,0
“Pure epoxy resin showed peaks near 856 which might be due to oxirane functionality of the epoxidized novolac resin.”
Srivastava 等 - 2018 - Studies on the structural changes during curing of DOI: 10.1016/j.saa.2017.06.066 -
Carbonate confianza 1,0
“In addition, characteristic bands of bidentate carbonates can be visualized at 1576, 1290, 1013, and 856 cm-1, corresponding to the stretching modes υas (CO3) for the first two bands, υs (CO3) for the following, and π (CO3) for the last [88”
CO2 Methanation over Nickel Catalysts: Support Effects Investigated through Specific Activity and Operando IR Spectroscopy Measurements DOI: 10.3390/catal13020448 -
Alkyl C-H confianza 1,0
“for example, Figure single aryl CH vibration was observed at 856 for lignin g-h °C, shows foams fabricated at 300, 500, 700, and 900 and but was not observed for WS or SBP (Figure 4a,d).”
Gupta 等 - 2020 - On the Design of Novel Biofoams Using Lignin, Whea DOI: 10.1021/acsomega.0c00721 -
Acetate confianza 1,0
“The absorbance bands around 856, 930, 996, 1077, 1149, cm-1 and 1242 were related to the C-O stretching, C-H rocking vibrations, and C-O-C”
Extraction and Characterization of Potential Biodegradable Materials Based on Dioscorea hispida Tubers DOI: 10.3390/polym13040584 -
confianza 1,0
“Figure 6e,f present Ni 2p XPS spectra, revealing the existence of peaks at binding energies 855.5 eV and 873.4 eV representing Ni 2p and Ni 2p 1/2, respectively, and the separating energy is”
Nickel Oxide-Carbon Soot-Cellulose Acetate Nanocomposite for the Detection of Mesitylene Vapour: Investigating the Sensing Mechanism Using an LCR Meter Coupled to an FTIR Spectrometer DOI: 10.3390/nano -
confianza 1,0
“The Ni2p spectrum displays a main peak at 856.1 eV attributed to Ni(OH) 2.”
Synthesis of NiFeOx nanocatalysts from metal–organic precursors for the oxygen evolution reaction DOI: 10.1039/D2DT01370C -
confianza 1,0
“Peaks at 855.65 and 872.90 eV indicates to Ni 2p3/2 2p1/2 and Ni energy levels, respectively.”
Ni(OH)2-decorated nitrogen doped MWCNT nanosheets as an efficient electrode for high performance supercapacitors DOI: 10.1038/s41598-019-42281-z
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