What absorbs at 3293 cm⁻¹ in an FTIR spectrum?
Una banda cerca de 3293 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 3293 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 |
|---|---|---|---|
| N h | 5 | 5 | 1,0 |
| Alkyl C-H | 5 | 5 | 1,0 |
| Hydroxyl (O-H) | 5 | 5 | 1,0 |
| Amide | 2 | 2 | 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 |
| Carboxyl (COOH) | 1 | 1 | 1,0 |
| Phenolic | 1 | 1 | 0,8 |
La clasificación refleja la evidencia acumulada de la literatura, no una única regla autorizada. Siempre confirme según el contexto de su muestra.
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 3293 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
-
Alkyl C-H confianza 1,0
“cm-1) The acetylenic C≡C bond stretching (2110 and acetylenic ≡C-H bond stretching (3293 peaks of 2-ethynylpyridine monomer were not seen in the FT-IR spectrum of polymer.”
Gal 等 - 2016 - Synthesis and Characterization of a Water-Soluble DOI: 10.12693/APhysPolA.129.642 -
Hydroxyl (O-H) confianza 1,0
“As observed, 𝜈, cm-1 a dominant broad peak centered at 3293 is due to the hydroxyl stretching vibrations.”
Power-Dependent Nonlinear Optical Behaviours of Ponceau BS Chromophore at 532 nm via Z-Scan Technique DOI: 10.1016/j.jphotochem.2020.112574 -
Alkyl C-H confianza 1,0
“- - - - O-H asymmetric and symmetric stretching 3293 3356 C-H asymmetric and symmetric stretching 2876 2872 2881 2858 2851 2851 vibration - - - - C=O stretching in aldehydes 1772 1778 - - - - - N-H bending of NH group (scissoring) 1673 2 -”
Sukprasert 等 - 2020 - Synchrotron FTIR Light Reveals Signal Changes of B DOI: 10.1155/2020/6149713 -
confianza 1,0
“sin2 1.83 N-H bend 1184 131 N-H(cid:5)(cid:5)(cid:5) stretching 3293 249 N-H stretching 3345”
Ay 和 Aydinli - 2004 - Comparative investigation of hydrogen bonding in s DOI: 10.1016/j.optmat.2003.12.004 -
Hydroxyl (O-H) confianza 1,0
“In the spectrum of pure capsaicin, the broad cm-1 cm-1 absorption peaks at 3293.43 and 2926.43 might be associated with the stretching of -OH bond and -C-H aliphatic stretching vibrations, respectively;”
Microencapsulation of Capsaicin in Chitosan Microcapsules: Characterization, Release Behavior, and Pesticidal Properties against Tribolium castaneum (Herbst) DOI: 10.3390/insects14010027 -
confianza 1,0
“Peaks observed at 3293 cm-1 cm-1 3293 and 3363 are indicative of the presence of the stretching vibrations of the amine group cm-1 and 3363 cm-1 are indicative of the presence of the stretching vibrations of the amine group in the”
Effect of the Zwitterion, p(MAO-DMPA), on the Internal Structure, Fouling Characteristics, and Dye Rejection Mechanism of PVDF Membranes DOI: 10.3390/membranes10110323 -
confianza 1,0
“A strong peak at 3293 was designated as the N-H stretching vibration of the peptide groups and termed amide A.”
Extracellular vesicles derived from microgreens of Raphanus sativus L. var. caudatus Alef contain bioactive macromolecules and inhibit HCT116 cells proliferation DOI: 10.1038/s41598-022-19950-7 -
Hydroxyl (O-H) confianza 1,0
“Effect of virus titer on characteristic spectra peak height The most significant differences were found for the at 8 h.p.i cm-1, peak at 3293 The characteristic peaks of the BGMK cell line showed assigned to OH stretching (One-way 106 chang”
Lee-Montiel 等 - 2011 - Detection and quantification of poliovirus infecti DOI: 10.1186/1754-1611-5-16
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