What absorbs at 727 cm⁻¹ in an FTIR spectrum?
Una banda cerca de 727 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 7 cited sources
Quick answer
A band near 727 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 |
| Alkene (C=C) | 2 | 2 | 1,0 |
| Metal oxygen | 2 | 2 | 1,0 |
| Ring structure | 1 | 1 | 1,0 |
| Aromatic ring | 1 | 1 | 1,0 |
| Secondary amine | 1 | 1 | 1,0 |
| C n single bond | 1 | 1 | 1,0 |
| Amide | 1 | 1 | 1,0 |
| N h | 1 | 1 | 1,0 |
| Carbonate | 1 | 1 | 0,9 |
La clasificación refleja la evidencia acumulada de la literatura, no una única regla autorizada. Siempre confirme según el contexto de su muestra.
Possible materials
| Material | Supporting peaks | Overlapping groups | Fuentes citadas |
|---|---|---|---|
| Silver Nanoparticles | 727, 1636, 1631 | Alkyl C-H | 1 |
Materials are shown only when the same literature pool supports this band and at least one additional characteristic peak.
Spectrum logic
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 727 cm⁻¹ is usually not enough for material identification by itself.
Real-world usage
This type of query is common in polymer identification, unknown plastic screening, QC troubleshooting, recycled-material verification, and literature-backed peak assignment review.
Common mistakes
- Treating one isolated band as proof of a material without checking at least one or two supporting peaks.
- Ignoring overlap: multiple functional groups can contribute near the same wavenumber.
- Skipping validation when additives, blends, oxidation, or contamination may distort the spectrum.
Verification advice
When ambiguity remains, validate the hypothesis with DSC, GC-MS, or TGA, especially for blends, degraded samples, and filled polymers.
Literatura detrás de estas asignaciones
-
Alkyl C-H confianza 1,0
“aromatic group in strong (C-H bend stretch, aliphatic amines group in medium (C-N stretch, 1055.96, 1038.12cm-1), alkenes group in strong (C-H rock, 981.81, 726.78cm-1), and alkyl halides group in medium (C-Br 567.83cm-1).”
Baranitharan 等 - 2022 - Fabrication of Silver Nanoparticles Using Fimbrist DOI: 10.1155/2022/4083663 -
Metal oxygen confianza 1,0
“856 0.47 0.59 Al-O stretching 727 0.5 0.6 653 0.5 0.6 Table 5: DRIFT bands that are characterizing coated and bonded”
El-Naggar - 2013 - Characterization of Modified and Polymer Coated Al DOI: 10.1155/2013/706960 -
Aromatic ring confianza 1,0
“Weaker bands at 727, 1022, and 1413 assigned to aromatic CH out of plane bending, aromatic CH in-plane”
Binational survey of personal protective equipment (PPE) pollution driven by the COVID-19 pandemic in coastal environments: Abundance, distribution, and analytical characterization DOI: 10.1016/j.jhazmat.2021.128070 -
Metal oxygen confianza 1,0
“LLM confirmed rule peak-group candidate”
Effect of aluminum fluoride complexation on fluoride removal by coagulation DOI: 10.1016/j.colsurfa.2011.12.010 -
Alkene (C=C) confianza 1,0
“The weak absorption peak at 727 belongs to the rocking double bonds.”
Characterization of the Materials and Techniques of Red Lacquer Painting of a Horizontal Plaque Inscribed by General Feng Yü-hsiang DOI: 10.3390/coatings13030583 -
Carbonate confianza 0,9
“Assigned to out-of-plane bending (ν4) of CO32-.”
Reyes 等 - 2021 - Kinetics of the Thermal Decomposition of Rhodochro DOI: 10.3390/min11010034 -
confianza 0,9
“in-plane bending vibration CO at 750 and 727”
Zhang 等 - 2019 - A Micro-Scale Investigation of the Adsorption of C DOI: 10.1007/s42461-019-00118-3
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