What absorbs at 1547 cm⁻¹ in an FTIR spectrum?
A band near 1547 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 1547 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 |
|---|---|---|---|
| Amide | 24 | 21 | 1.0 |
| N h | 10 | 10 | 1.0 |
| Secondary amine | 9 | 9 | 1.0 |
| C n single bond | 6 | 6 | 1.0 |
| Carbonyl (C=O) | 4 | 4 | 1.0 |
| Aromatic ring | 2 | 2 | 1.0 |
| Methacrylate | 2 | 2 | 1.0 |
| Carboxyl (COOH) | 2 | 2 | 1.0 |
| Acetate | 2 | 2 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Protein beta sheet | 1 | 1 | 1.0 |
| Protein | 1 | 1 | 1.0 |
| Carbohydrate | 1 | 1 | 1.0 |
| Alkene (C=C) | 1 | 1 | 1.0 |
| Ketone | 1 | 1 | 1.0 |
| Ester | 1 | 1 | 1.0 |
| Methoxy (OCH3) | 1 | 1 | 1.0 |
| C-O single bond | 1 | 1 | 1.0 |
| Protein alpha helix | 1 | 1 | 0.9 |
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 |
|---|---|---|---|
| ZnO | 1547, 1400, 3430 | Amide | 1 |
| nanoparticles | 1547, 1732, 1647 | Amide | 1 |
| cellulose | 1547, 1735, 1650 | Amide | 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 1547 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
-
Amide confidence 1.0
“The peaks at 1631 are due to C=O stretching in amide group while the cm-1 cm-1 C-N C-N peak at 1547 is deformation in amide group and the peak at 1147 is cm-1 in Bt stretching in amide group.”
Development of a water dispersible granule (WDG) formulation of Bacillus thuringiensis for the manag DOI: 10.1080/09583157.2021.1895073 -
Acetate confidence 1.0
“The 90 cm-1 peaks at 1547 and 1502 represents the C O and loss”
Hadia 等 - 2014 - Effect of the Temperature on Structural and Optica DOI: 10.1166/jnn.2014.8861 -
Carboxyl (COOH) confidence 1.0
“In the region of the IR band could (1615cm-1) be assigned as the ionized asymmetric carboxylate 1547cm-1), 3+ and NH deformation vibration (1567 (shoulder) and 1350cm-1, these bands corresponded respectively.”
Hsu 和 Lin - 2009 - Rapid examination of the kinetic process of intram DOI: 10.1016/j.tca.2008.12.008 -
Amide confidence 1.0
“Furthermore, this peak can be ascribed to the amide I band [24], A totally different situation is observed in the samcm-1 that can be since a weak absorption peak at 1547 ple of sulfate pulp infected with P.”
Povolotckaia 等 - 2019 - Biodamage to Paper by Micromycetes under Experimen DOI: 10.1134/S0030400X19040209 -
Amide confidence 1.0
“The and a small shoulder peak at 1442 in the yeast spectrum Karolinska cm-1 amide II peak at 1547 (0 h, Fig.”
Shi 等 - 2018 - Biochemical alterations of Candida albicans during DOI: 10.1039/c8an01452c -
Amide confidence 1.0
“LLM confirmed rule peak-group candidate”
Song 等 - 2019 - Physicochemical and Biocompatibility Properties of DOI: 10.3390/md17030137 -
Acetate confidence 1.0
“2919cm-1 teristic peaks were at 1778 and amide A), (C-H asymmetric and symmetric 1654cm-1 2851cm-1 In this case, the peak at about stretching vibration), was the imine (C-H asymmetric and sym1652cm-1 bond (C=N), which could be ascribed as t”
Sukprasert 等 - 2020 - Synchrotron FTIR Light Reveals Signal Changes of B DOI: 10.1155/2020/6149713 -
Amide confidence 1.0
“LLM confirmed rule peak-group candidate”
Proteomic profiling of platelet proteins by trypsin immobilized self-assembled monolayers digestion chip and protein identification using electrospray ionization tandem mass spectrometry DOI: 10.1002/jbm.a.30129
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