What absorbs at 1243 cm⁻¹ in an FTIR spectrum?
Una banda cerca de 1243 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 1243 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 |
|---|---|---|---|
| C-O single bond | 12 | 12 | 1,0 |
| Methoxy (OCH3) | 11 | 11 | 1,0 |
| Methacrylate | 11 | 11 | 1,0 |
| Acetate | 11 | 11 | 1,0 |
| Amide | 7 | 7 | 1,0 |
| Alkyl C-H | 6 | 6 | 1,0 |
| Secondary amine | 5 | 5 | 1,0 |
| C n single bond | 4 | 4 | 1,0 |
| Hydroxyl (O-H) | 3 | 3 | 1,0 |
| Phosphate (PO4) | 3 | 3 | 1,0 |
| Aromatic ring | 2 | 2 | 1,0 |
| N h | 2 | 2 | 1,0 |
| Ring structure | 2 | 2 | 1,0 |
| Carbonyl (C=O) | 2 | 2 | 1,0 |
| Ester | 2 | 2 | 1,0 |
| Carboxyl (COOH) | 2 | 2 | 1,0 |
| Alkene (C=C) | 1 | 1 | 1,0 |
| C c single bond | 1 | 1 | 1,0 |
| Nucleic acid | 1 | 1 | 1,0 |
| Phosphorus | 1 | 1 | 1,0 |
| Carbohydrate | 1 | 1 | 1,0 |
| Lignin | 1 | 1 | 1,0 |
| Ketone | 1 | 1 | 1,0 |
| Methyl | 1 | 1 | 1,0 |
| Phospholipid | 1 | 1 | 0,9 |
| Fluorine (C-F) | 1 | 1 | 0,7 |
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 |
|---|---|---|---|
| Cellulose | 1243, 1735, 1650 | Acetate, Methacrylate, C-O single bond | 1 |
| asphalt binder | 1243, 1700, 1242 | Methacrylate, Acetate | 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 1243 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
“shoulder band at about The 1459 and 1384cm-1 bands are methyl bending signals and bands at 1243”
Font 等 - 2007 - Fourier transform infrared spectroscopy as a suita DOI: 10.1016/j.aca.2007.07.021 -
Acetate confianza 1,0
“The peak at wavelength The ratio of cellulose to concentration as a EFB AA cm-1 1243 is attributed to the stretching of and C-O C=O modified reagent played a significant role on the WPG deformation of the ester bond.”
Jahi 等 - 2020 - Empty Fruit Bunch Cellulose based Sorbent for Oil DOI: 10.17576/jsm-2020-4909-29 -
Alkyl C-H confianza 1,0
“(690-900 C-O (970-1250 and stretching A peak at cm-1 C-H 1243.26 may be assigned to bonding.”
Synthesis and characterization of a green‐light‐emitting (pbi‐Br)2Ir (acac) metal complex for OLEDs DOI: 10.1002/bio.3565 -
Acetate confianza 1,0
“However, peak at cm-1 1243 was absence upon acid hydrolysis due to the removal of C-O-C functional group of aryl-alkyl ether in 460 lignin [17].”
Kuthi 和 Badri - 2014 - Effect of Cooking Temperature on the Crystallinity DOI: 10.1063/1.4895240 -
Alkyl C-H confianza 1,0
“Related studies have confirmed that when EVA is added to a modified asphalt is peak-responsive in wavenumber of 1243 and 1740 by the combination of cm(cid:2879)(cid:2869) cm(cid:2879)(cid:2869) binder, it is peak-responsive in wavenumber of”
Analysis of the Properties of Modified Asphalt Binder by FTIR Method DOI: 10.3390/ma15165743 -
Amide confianza 1,0
“FTIR spectra Implants of FIB and HA-FIB films exhibited distinctive absorption maxima, in specific positions of FIB random MatrixAssistedPulsedLaserEvaporation 1540cm-1 1654cm-1 1243cm-1 1027cm-1 (MAPLE) coil form: amide II, amide I, amide”
Composite biocompatible hydroxyapatite⠍silk fibroin coatings for medical implants obtained by Matrix Assisted Pulsed Laser Evaporation DOI: 10.1016/j.mseb.2009.10.004 -
C-O single bond confianza 1,0
“and multiple CF band (1243, 1190, 800,and 748 From Figure 2 shows asymmetric stretching mode of ether funcFig.”
Radzir 等 - 2015 - Effect of lithium bis(trifluoromethylsulfonyl)imid DOI: 10.1007/s10008-015-2910-z -
Amide confianza 1,0
“purine = √ D L(cid:4)H (6) A0˛,A(cid:4)L(cid:4)˛(cid:4) A(cid:4)˛(cid:4) (cid:3) A˛, m Am cm-1 A(cid:4) The vibration at 1243 comes from the in-plane stretching of the C N bonds and the stretching and in-plane swinging of where”
A comparative study on the experimental and calculated results of mid-infrared and Raman vibrational modes of nucleic acid bases DOI: 10.1016/j.jmgm.2017.04.016
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