What absorbs at 3680 cm⁻¹ in an FTIR spectrum?
Una banda cerca de 3680 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 3680 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 |
|---|---|---|---|
| Hydroxyl (O-H) | 8 | 7 | 1,0 |
| Carboxyl (COOH) | 1 | 1 | 1,0 |
| Water (H2O) | 1 | 1 | 1,0 |
| N h | 1 | 1 | 1,0 |
| Hydrogen bond | 1 | 1 | 1,0 |
| Acetate | 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.
Materiales posibles
| Material | Picos de apoyo | Grupos superpuestos | Fuentes citadas |
|---|---|---|---|
| polyurethane | 3680, 2270, 1700 | N h | 1 |
| TiO2 | 3680, 1700, 1093 | Hydroxyl (O-H), Carboxyl (COOH) | 1 |
| water | 3680, 1018, 2945 | Hydroxyl (O-H), Water (H2O) | 1 |
| zirconia | 3680, 1100, 460 | Hydroxyl (O-H), Carboxyl (COOH), Water (H2O) | 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 3680 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
-
Hydroxyl (O-H) confianza 1,0
“The double peaks at 3680 cm-1 and 3633 cm-1 were observed due to the stretching vibration of the hydroxyl group at the surface of HNTs.”
Synthesis and Optimization of Superhydrophilic-Superoleophobic Chitosan–Silica/HNT Nanocomposite Coating for Oil–Water Separation Using Response Surface Methodology DOI: 10.3390/nano12203673 -
confianza 1,0
“The group of peaks from 3680 cm-1 to 3482 cm-1 intense spectral features at 938 and 3680 cm-1 correspond to the position of peaks that arise from OHstretching modes, where OHgroups are bound to Mg (serpentine and stitchtite) or Cr (stitchti”
Melchiorre 等 - 2020 - Insights on Structure and Threshold Detection Limi DOI: 10.3390/min10030215 -
Hydroxyl (O-H) confianza 1,0
“spectra with similar features in this region, in addition to a free Figure 2c shows the probability of a water molecule forming cm-1.22,25,95 cm-1 ∼3680 The 3200 peak has been OH stretch at a particular number of hydrogen bonds within the d”
Moussa 等 - 2009 - Experimental and Theoretical Characterization of A DOI: 10.1021/jp808710n -
Hydroxyl (O-H) confianza 1,0
“The vibrational bands at between between 3680 cm-1 and 3120 cm-1 are due to O-H and N-H stretching and can be attributed to cm-1 cm-1 between 3680 cm-1 and 3120 cm-1 are due to O-H and N-H stretching and can be attributed to 3680 and 3120 a”
Self-Healable Supramolecular Vanadium Pentoxide Reinforced Polydimethylsiloxane-Graft- Polyurethane Composites DOI: 10.3390/polym11010041 -
Hydroxyl (O-H) confianza 1,0
“CO stretching asym CaCO3 cm-1, 1050-1015 SO stretching Ca(SO4)·2H2O An intense band, between 3680 and 3000 is related to the OH stretchings of celcm-1 870-880 CO stretching asym CaCO3 lulose [46] and absorbed water, while the bending of thi”
Water-Based Aerosol for Book Deacidification: Experimental Apparatus and Theoretical Interpretation of Results DOI: 10.3390/molecules26144249 -
Hydroxyl (O-H) confianza 1,0
“The band of isolated OH groups at 3772 disappeared nearly completely, whereas the intensity of the cm1 hydroxyl stretch vibration band at 3680 decreased”
Adsorption and Reaction of CO on (Pd–)Al2O3 and (Pd–)ZrO2: Vibrational Spectroscopy of Carbonate Formation DOI: 10.1007/s11244-017-0852-7 -
Hydroxyl (O-H) confianza 1,0
“The results are presented in Table 2 that spectra of feedstock mainly possess peaks at around 3680cm-1 cm-1 O-H lignin, 1 3000 are assigned to stretching from peaks around 3000-2800 represent the C-H stretching 3 D cm-1”
Jaruwat 等 - 2018 - Effects of Hydrothermal Temperature and Time of Hy DOI: 10.1063/1.5053192 -
Hydroxyl (O-H) confianza 1,0
“This spectrum Scientific), low-temperature chamber (Harrick evacuated to the lowest (3725cm-1, exhibits IR bands of surface hydroxyls of anatase (ca.<10-3mbar) stable pressure and kept under dynamic vacuum for 3632cm-1) (3680cm-1, 3414cm-1)”
Litke 等 - 2019 - Interfacial charge transfer in Pt-loaded TiO2 P25 DOI: 10.1016/j.jphotochem.2018.10.023
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