What absorbs at 881 cm⁻¹ in an FTIR spectrum?
A band near 881 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 881 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.
Possible functional-group assignments
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| Alkyl C-H | 4 | 4 | 1.0 |
| Methoxy (OCH3) | 2 | 2 | 1.0 |
| Methacrylate | 2 | 2 | 1.0 |
| C-O single bond | 2 | 2 | 1.0 |
| Acetate | 2 | 2 | 1.0 |
| C c single bond | 1 | 1 | 1.0 |
| Phosphate (PO4) | 1 | 1 | 1.0 |
| Hydroxyl (O-H) | 1 | 1 | 1.0 |
| Metal oxygen | 1 | 1 | 1.0 |
| Amine primary | 1 | 1 | 1.0 |
| N h | 1 | 1 | 1.0 |
Ranking reflects accumulated literature evidence, not a single fixed rule. Always confirm against your sample context.
Possible materials
| Material | Supporting peaks | Overlapping groups | Cited sources |
|---|---|---|---|
| PANi | 881, 2930, 1300 | Alkyl C-H | 1 |
| hydroxyapatite | 881, 1620, 1639 | Alkyl C-H, Methacrylate | 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 881 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.
Literature behind these assignments
-
Alkyl C-H confidence 1.0
“cm-1 1, C-F stretching, 881 C-H rocking, 881, 838”
Lead titanate/cyclic carbonate dependence on ionic conductivity of ferro/acrylate blend polymer composites DOI: 10.1063/1.4948194 -
Alkyl C-H confidence 1.0
“Another specific band of aniline also are confirmed at 881 cm-1 cm-1 and 748 as bending vibration of C-H and wag vibration of N-H from primary amine.”
International Conference on Innovation on Polymer Science and Technology DOI: 10.1088/1757-899X/223/1/012051 -
confidence 1.0
“The blue shift of by the influence of Mn g cm-1 band observed at 881 is associated with the presence is due to the increase of carrier density generated by Mn of defect state surrounding Mn/Mg ions in Zn-O lattice.”
Phyto-assisted Synthesis of Mn and Mg Co-doped ZnO Nanostructures Using DOI: 10.1007/s12668-021-00890-x -
Hydroxyl (O-H) confidence 1.0
“OH stretching beidellite DRD 881, 925 OH liberation mode associated with Al-OH octahedra (Al-OH-AL)”
Micro-characterization of Dust and Materials of Dust Origin at a Cement Industry Located in Bangladesh DOI: 10.4209/aaqr.220109 -
Alkyl C-H confidence 1.0
“LLM confirmed rule peak-group candidate”
Assessment of quality of commercial hand sanitizers using Fourier transform infrared spectroscopy and gas chromatography DOI: 10.1016/j.mex.2023.102274 -
Phosphate (PO4) confidence 1.0
“43vibration mode of the functional group PO The bands at 881, evidence the P-O stretching vibrations in PO group [25].”
Perju 等 - 2022 - SOME ASPECTS CONCERNING TITANIUM COVERAGE WITH HYD DOI: 10.24425/amm.2022.137785 -
Alkyl C-H confidence 1.0
“350°C-450 cm-1 °C Similarly, the band at 881.34 represents C-H out-of-plane (11.6%) indicates the breakdown of the polymer”
Sulaimon 等 - 2023 - Quantitative and qualitative analyses of grafted o DOI: 10.3389/fchem.2023.1129673 -
C c single bond confidence 1.0
“Likewise, the s(C-C) + s(CF 2) band at 881 and cm-1, δ(C-F δ(C-F the duplet bands located at 480 and 510 correlated to the 2), and 2) +”
Torres-Rodriguez 等 - 2022 - Polyvinylidene Fluoride Aerogels with Tailorable C DOI: 10.3390/gels8110727
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