What absorbs at 861 cm⁻¹ in an FTIR spectrum?
A band near 861 cm⁻¹ can point to several functional groups. Below are the most likely assignments, ranked by how much published evidence supports each — every one traceable to literature (DOI) and cross-validated against our 130,000+ reference spectra and knowledge graph.
Backed by 8 cited sources
Quick answer
A band near 861 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.
Attributions possibles de groupes fonctionnels
| Groupe fonctionnel | Faits à l＇appui | Sources citées | Confiance maximale |
|---|---|---|---|
| Alkyl C-H | 4 | 4 | 1,0 |
| Amide | 3 | 3 | 1,0 |
| Methacrylate | 3 | 3 | 1,0 |
| Acetate | 3 | 3 | 1,0 |
| Silicon-oxygen (Si-O) | 2 | 2 | 1,0 |
| Ketone | 2 | 2 | 1,0 |
| Ester | 2 | 2 | 1,0 |
| Carboxyl (COOH) | 2 | 2 | 1,0 |
| Carbonyl (C=O) | 2 | 2 | 1,0 |
| Methoxy (OCH3) | 2 | 2 | 1,0 |
| C-O single bond | 2 | 2 | 1,0 |
| Aromatic ring | 2 | 2 | 1,0 |
| Secondary amine | 2 | 2 | 1,0 |
| C n single bond | 2 | 2 | 1,0 |
| Hydroxyl (O-H) | 2 | 1 | 1,0 |
| Silicon (Si) | 1 | 1 | 1,0 |
| N-O bond | 1 | 1 | 1,0 |
| N h | 1 | 1 | 1,0 |
| Metal oxygen | 1 | 0 | 1,0 |
Le classement reflète les preuves bibliographiques accumulées, et non une règle faisant autorité. Confirmez toujours dans le contexte de votre échantillon.
Possible materials
| Matériel | Pics de support | Overlapping groups | Sources citées |
|---|---|---|---|
| starch | 861, 1650, 1540 | Methacrylate, Acetate, Alkyl C-H | 1 |
| humic acid | 861, 1660, 1220 | Alkyl C-H, Methacrylate, Acetate | 1 |
| PE | 861, 1414, 1700 | Alkyl C-H, Methacrylate, Acetate | 1 |
| PP | 861, 1700, 1043 | Alkyl C-H, Methacrylate, Acetate | 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 861 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.
Bibliographie derrière ces attributions
-
Acetate confiance 1,0
“The bands at about cm-1 cm-1 ∼1033 ∼1082 and are assigned to the coupling bands of the skeletal vibrational modes of cm-1 cm-1 ∼861 ∼881 C-O and C-C stretching vibration modes.”
Guo 等 - 2018 - Observation of conformational changes in ethylene DOI: 10.1063/1.4995975 -
Alkyl C-H confiance 1,0
“Moreover, the absorption weak absorption band at 861.22 was assigned to C-H bending of aromatic compounds.”
Facile Green Synthesis of Zinc Oxide Nanoparticles with Potential Synergistic Activity with Common Antifungal Agents against Multidrug-Resistant Candidal Strains DOI: 10.3390/cryst12060774 -
Alkyl C-H confiance 1,0
“Further bands at 861, 1261 and 1413 were assigned to CH vibra3”
Optical photothermal infrared spectroscopy with simultaneously acquired Raman spectroscopy for two-dimensional microplastic identification DOI: 10.1038/s41598-022-23318-2 -
N h confiance 1,0
“The other common overlapping ranges included 1712 (for water [31]), 1530 cm-1-1560 cm-1 (for coupled NH deformation and C-N stretching [32]), and near 861 cm-1”
Variety Identification of Orchids Using Fourier Transform Infrared Spectroscopy Combined with Stacked Sparse Auto-Encoder DOI: 10.3390/molecules24132506 -
Amide confiance 1,0
“-NHbond vibration peaks are at 1453 cm-1 (in-plane bending) and 861 cm-1 (out-of-plane cm-1 is the stretching vibration peak of the C-N bond and 1050 is the stretching vibration peak of the”
Inhibition of Poly(ethylenediaminetetraacetic acid-diethanolamine) on Deposition of Calcium Sulfate Crystal in Simulated Industrial Water DOI: 10.3390/cryst10060544 -
Aromatic ring confiance 1,0
“In addition to aromatic C-H bending, cm-1 protein and subsequently caused aggregation between unfoldthe peak at 861 may also indicate the presence of an ed proteins or dissociated low MW subunits via hydrophobic indolering, possibly by the”
Effect of maleylation on physicochemical and functional properties of rapeseed protein isolate DOI: 10.1007/s13197-016-2197-9) -
Acetate confiance 1,0
“2, OH bond scissoring, molecule substitution Xylose, Amygdalin 1726.95, 1646.78, 929.23, skeletal stretch, C=O, C-O stretch 861.14, 763.13 b-cyclodextrin, a-cyclodextrin, Yellow Native 3390.46, 2930.19, 2150.35, CH OH, C=O stretch, OH bend,”
Influence of physical and chemical modifications on granule size frequency distribution, fourier transform infrared (FTIR) spectra and adsorption isotherms of starch from four yam (Dioscorea spp.) cultivars DOI: 10.1007/s13197-021-05200-7 -
N-O bond confiance 1,0
“TOC, a new peak at 861 is seen possibly due to can interact with one or more HA molecules N-O stretching.”
Saxena 和 Brighu - 2020 - Optimized coagulation of humic acid and mineral tu DOI: 10.2166/ws.2020.141
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