What absorbs at 1487 cm⁻¹ in an FTIR spectrum?
A band near 1487 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 1487 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 |
|---|---|---|---|
| Aromatic ring | 3 | 3 | 1.0 |
| Alkyl C-H | 3 | 3 | 1.0 |
| Ring structure | 3 | 3 | 1.0 |
| C c single bond | 3 | 3 | 1.0 |
| Alkene (C=C) | 2 | 2 | 1.0 |
| Secondary amine | 2 | 2 | 1.0 |
| Amide | 2 | 2 | 1.0 |
| C n single bond | 1 | 1 | 1.0 |
| N h | 1 | 1 | 1.0 |
| N-O bond | 1 | 1 | 1.0 |
| Borate | 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 |
|---|---|---|---|
| polyaniline | 1487, 1565, 1570 | Aromatic ring, Alkyl C-H, Ring structure | 2 |
| PEG | 1487, 1650, 1342 | Alkyl C-H | 1 |
| copolymer | 1487, 2921, 1540 | Alkyl C-H | 1 |
| membrane | 1487, 1316, 2927 | Alkyl C-H, Aromatic ring | 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 1487 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
-
C c single bond confidence 1.0
“The peaks at 1487 1454cm-1 -COOν and are due to the between and C-C”
Das 等 - 2004 - Kinetics and adsorption behaviour of salicylate on DOI: 10.1016/j.colsurfa.2004.02.010 -
Alkene (C=C) confidence 1.0
“Explicit assignment.”
Dey Sadhu 等 - 2020 - Preparation and characterization of polyanilinea DOI: 10.1002/pc.25738 -
C c single bond confidence 1.0
“cm-1 cm-1 1487 is corresponds to C C stretching vibration of benzoniod ring, 1302 is cm-1 N bonds of aromatic amines 1236 corresponds to C N due to the stretching of C cm-1 corresponds to C H in plane of aromatic rings stretching of benzoni”
Patil 等 - 2011 - Electrical Conductivity of PolyanilineNiZnO3 Comp DOI: 10.1080/00150193.2011.620836 -
Borate confidence 1.0
“Anti-symmetric stretching vibra- (NBO's) B-O-B tions with three non-bridging oxygens of groups were cm(cid:0) 1 identified with the bands around 1487 in all the glasses.”
Influence of BaO on spectral studies of Cr2O3 doped titanium-boro-tellurite glasses DOI: 10.1016/j.optmat.2020.110329 -
Alkyl C-H confidence 1.0
“cm(cid:1)1 cm(cid:1)1 2849 combination band, the 1487 CH asymmetric 3 cm(cid:1)1 deformation band, the 1450 CH scissoring band, or the”
Vibrational Stark effect (VSE) on the infrared spectrum of a poly(methyl methacrylate) thin film DOI: 10.1016/j.vibspec.2015.03.006 -
C c single bond confidence 1.0
“LLM confirmed rule peak-group candidate”
A Comparison of the Effect of Cellulose Nanocrystals (CNCs) and Polyethylene Glycol (PEG) as Additives in Ultrafiltration Membranes (PES-UF): Characterization and Performance DOI: 10.3390/polym15122636 -
Aromatic ring confidence 1.0
“311 312 All the membranes showed typical spectrum of PES material, aromatic bands at 1577 313 cm-1 cm-1 and 1487 from the benzene ring stretching and C-C bond stretching,”
Garcia-Ivars 等 - 2014 - Development of fouling-resistant polyethersulfone DOI: 10.1016/j.seppur.2014.07.056. -
N-O bond confidence 1.0
“cm(cid:2)1, cm(cid:2)1 reconstituted into PS1 we observe no band at 1487 decreases in intensity Second, a positive band at 1494 on18Olabeling, 9.”
Time-Resolved FTIR Difference Spectroscopy in Combination with Specific Isotope Labeling for the Study of A1, the Secondary Electron Acceptor in Photosystem 1 DOI: 10.1529/biophysj.107.113191
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