What absorbs at 1518 cm⁻¹ in an FTIR spectrum?
Una banda cerca de 1518 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 1518 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 |
|---|---|---|---|
| Amide | 7 | 7 | 1,0 |
| Aromatic ring | 5 | 4 | 1,0 |
| Alkene (C=C) | 4 | 4 | 1,0 |
| Alkyl C-H | 4 | 4 | 1,0 |
| Methacrylate | 3 | 3 | 1,0 |
| C-O single bond | 3 | 3 | 1,0 |
| Acetate | 3 | 3 | 1,0 |
| Protein beta sheet | 2 | 2 | 1,0 |
| N h | 2 | 2 | 1,0 |
| Methoxy (OCH3) | 2 | 2 | 1,0 |
| C c single bond | 2 | 2 | 1,0 |
| Protein | 2 | 1 | 1,0 |
| N-O bond | 2 | 1 | 1,0 |
| Carbonyl (C=O) | 2 | 1 | 1,0 |
| Protein alpha helix | 1 | 1 | 1,0 |
| Water (H2O) | 1 | 1 | 1,0 |
| Phosphate (PO4) | 1 | 1 | 1,0 |
| Nitro (NO2) | 1 | 1 | 1,0 |
| Ketone | 1 | 1 | 1,0 |
| Ester | 1 | 1 | 1,0 |
| Carboxyl (COOH) | 1 | 1 | 1,0 |
| Hydroxyl (O-H) | 1 | 1 | 1,0 |
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 1518 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
“The band at 1518 is generally ascribed to cm-1 C-H bending vibration and the band at 1030 assigned to C-O stretching of acetyl groups present in PVA.”
Devi 等 - 2019 - Structural and optical studies on PVA capped SnS f DOI: 10.1088/1674-4926/40/5/052101 -
Protein confianza 1,0
“A which are characteristic of proteins were observed with a maximum at around 1634 and 1518 cm-1, cm-1) which are indicative of the amide I band (1750-1600 and amide II band (1550-1510 cm-1), respectively.”
Rafe 和 Razavi - 2015 - Effect of Thermal Treatment on Chemical Structure DOI: 10.1080/10942912.2014.999864 -
Aromatic ring confianza 1,0
“theae (PT) is phylogenetically related to 3deformations)andemercm(cid:1)1 (CAH Pestalotiopsis, which has been reported to decolourize raw textile gence of peaks at 1518.20 bending in aromatic ring)”
Decolourization of malachite green dye by endolichenic fungi from the lichen Usnea sp.: A novel study on their dye removal potential DOI: 10.1016/j.jksus.2021.101579 -
confianza 1,0
“Since the color of melanin is resulted 184 from the absorption of light by electrons of chromophores (dihydroxyindole units in the 185 cm-1 eumelanin), stronger peak at 1518 of the N-H and C-N bands of SI melanin explains the N”
Isolation and characterization of melanin from black garlic and sepia ink DOI: 10.1016/j.lwt.2018.09.033 -
C c single bond confianza 1,0
“and (iv) the appearance of two IR bands According to Figure 5, the IR spectrum of protein G is dominated by two IR bands with maxima at 1699 and 1780 cm-1, both assigned to the C=O vibrational mode whose cm-1, at 1518 and 1634 which were as”
Optical Evidence for the Assembly of Sensors Based on Reduced Graphene Oxide and Polydiphenylamine for the Detection of Epidermal Growth Factor Receptor DOI: 10.3390/coatings11020258 -
C c single bond confianza 1,0
“C = O stretch, O7-H22 bend, and ring A C-C stretch at 1518 cm-1 cm-1, and 1518 Table 1 presents the relative absorbances in the SC layers at 1652 which correspond to the amounts of GEN that penetrated into the SC after conventional and”
Balazs 等 - 2016 - ATR-FTIR and Raman spectroscopic investigation of DOI: 10.1364/BOE.7.000067 -
Alkene (C=C) confianza 1,0
“Weak band near 1518 our results of DPPH assay obtained for methanolic arose from C=C stretching vibrations of phenoextracts.”
Morphology, physicochemical properties and antioxidant capacity of bee pollens DOI: 10.17221/139/2018-CJFS -
Hydroxyl (O-H) confianza 1,0
“The hydroxyl groups bending vibrations exist at 1518 cm-1 and 1750 [34].”
Kinetics of Dehydroxylation and Decarburization of Coal Series Kaolinite during Calcination: A Novel Kinetic Method Based on Gaseous Products DOI: 10.3390/ma14061493
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