What absorbs at 869 cm⁻¹ in an FTIR spectrum?
Una banda cerca de 869 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 869 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 | 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 |
| Hydroxyl (O-H) | 1 | 1 | 1,0 |
| Aromatic ring | 1 | 1 | 1,0 |
| Silicon (Si) | 1 | 1 | 1,0 |
| Siloxane (Si-O-Si) | 1 | 1 | 1,0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1,0 |
| Metal oxygen | 1 | 1 | 1,0 |
| Carbonate | 1 | 0 | 1,0 |
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 |
|---|---|---|---|
| HCl | 869, 1708, 1032 | Methacrylate, C-O single bond, Methoxy (OCH3) | 1 |
| polycaprolactone | 869, 1580, 1751 | Methacrylate, Methoxy (OCH3), C-O single bond | 1 |
| PLA | 869, 1650, 1073 | Alkyl C-H, Methacrylate, Methoxy (OCH3) | 1 |
| PCL | 869, 1751, 1724 | Alkyl C-H, Methacrylate, Methoxy (OCH3) | 1 |
| biomass | 869, 1082, 1282 | Alkyl C-H, Methacrylate, C-O single bond | 1 |
| PAni | 869, 2930, 1300 | 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 869 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
“869cm-1 films C-H and at in PAni doped may be due to out of plane cm-1 film bending.”
Influence of polyaniline doping concentration in (Bi0.5Sb0.5)2S3 thin polycrystalline films on structural, electrical and optical properties DOI: 10.1016/j.jnoncrysol.2010.03.012 -
Metal oxygen confianza 1,0
“Another peak at cm-1 869 in the BFD spectrum, can occur from the Al-O stretching in AlO4 tetrahedra of aluminate, or from symmetric Si-O-Si stretching in SiO4 tetrahedra of alite (Ghosh and Handoo, 1980;”
Micro-characterization of Dust and Materials of Dust Origin at a Cement Industry Located in Bangladesh DOI: 10.4209/aaqr.220109 -
Aromatic ring confianza 1,0
“The presence of both bands together with the band at 869 due to the aromatic C-H out-of-plane bending vibrations, confirms the presence of a significant amount of hydrolysable tannins in the eucalyptus bark extract.”
Santos 等 - 2023 - Forest by-Product Valorization Pilot-Scale Pinus DOI: 10.3390/f14050895 -
Hydroxyl (O-H) confianza 1,0
“literatures10,17 cm-1 According to peak at 1065 is assigned to BRB-PMo hybrid was synthesized by addition of 0.05 12 cm-1 inner P-O a-Mo bond, peak at 790 to Mo-O d-Mo bridges, g/mL aqueous solution of butylrhodamine B dropwise to a cm-1 cm”
Zeng 等 - 2013 - Electrochemical and Fluorescent Investigation of I DOI: 10.14233/ajchem.2013.14039 -
Acetate confianza 1,0
“The following bands belong to PCL: C=O stretching (1724, 1182 valence cm-1), cm-1) C-O-C vibrations (869, 1043, and 1109 C=C stretching (1286 [28,33].”
Polymer Composite Materials Based on Polylactide with a Shape Memory Effect for “Self-Fitting” Bone Implants DOI: 10.3390/polym13142367 -
confianza 0,9
“Explicit assignment: 'deformation bands 869 cm-1 ... originating from PA'.”
Characterization of New Polymer Material of Amino–Cyclodextrin and Sodium Alginate for Environmental Purposes DOI: 10.3390/membranes13040447 -
confianza 0,8
“Micro-window centered at 869 cm-1 for HCl retrieval.”
Retrieval of Stratospheric HNO3 and HCl Based on Ground-Based High-Resolution Fourier Transform Spectroscopy DOI: 10.3390/rs13112159
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