What absorbs at 1554 cm⁻¹ in an FTIR spectrum?
A band near 1554 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 1554 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 | 14 | 14 | 1.0 |
| Carboxyl (COOH) | 6 | 6 | 1.0 |
| N h | 5 | 5 | 1.0 |
| Methacrylate | 5 | 5 | 1.0 |
| Carbonyl (C=O) | 5 | 5 | 1.0 |
| Acetate | 5 | 5 | 1.0 |
| Ketone | 3 | 3 | 1.0 |
| Ester | 3 | 3 | 1.0 |
| Secondary amine | 3 | 3 | 1.0 |
| C n single bond | 3 | 3 | 1.0 |
| Alkyl C-H | 3 | 2 | 1.0 |
| Methoxy (OCH3) | 2 | 2 | 1.0 |
| C-O single bond | 2 | 2 | 1.0 |
| Hydroxyl (O-H) | 2 | 2 | 1.0 |
| Ring structure | 2 | 1 | 1.0 |
| Hydrogen bond | 1 | 1 | 1.0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1.0 |
| Silicon (Si) | 1 | 1 | 1.0 |
| Aromatic ring | 1 | 1 | 1.0 |
| Alkene (C=C) | 1 | 1 | 1.0 |
| Nitrogen heterocycle | 1 | 1 | 1.0 |
| C c single bond | 1 | 1 | 1.0 |
| Carbohydrate | 1 | 1 | 1.0 |
| Protein | 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 |
|---|---|---|---|
| protein | 1554, 1650, 1640 | Amide, N h, Methacrylate | 1 |
| HDPE | 1554, 1369, 1216 | Methacrylate, Carboxyl (COOH) | 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 1554 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
-
Carboxyl (COOH) confidence 1.0
“While in cobalt stearate, the absorption peak at wave number of 1554 cm-1indicate the presence of asymmetric vibrations of carboxylate groups absorption peak at the wave numbers of 3000”
Asriza 和 Arcana - 2015 - SYNTHESIS OF COBALT STEARATE AS OXIDANT ADDITIVE F DOI: 10.1063/1.4930711 -
Amide confidence 1.0
“The difference between NRL and DPNRL cm-1, films was the absorption of primary amide stretching peak at 1661-1663 has shifted to 1554cm-1 1560 which was assigned to secondary amide N-H bending peak.”
Wei 等 - 2014 - An Optimization Study on the Inclusion of Aluminiu DOI: 10.4028/www.scientific.net/AMR.844.399 -
Amide confidence 1.0
“LLM confirmed rule peak-group candidate”
van Thor 等 - 2005 - Assignments of the Pfr-Pr FTIR difference spectrum DOI: 10.1021/jp052323t -
Protein confidence 1.0
“cm-1/1554 cm-1 The band ratio inspecting the spectral changes in the protein regions 1654 cm-1/1554 cm-1 The band ratio inspecting the spectral changes in the protein regions 1654 cm-1 has also been analyzed.”
Andjelic 等 - 2023 - Characterization of Different Types of Epiretinal DOI: 10.3390/ijms24054834 -
Acetate confidence 1.0
“Two peaks centered at 1651 cm-1 and 1554 cm-1 corresponding to carboxamide vibrations of the C-O-C bond and glycosides bridge a peak centered at 1155 Two peaks centered cm-1 cm-1”
Development of Polymer Blend Electrolyte Membranes Based on Chitosan: Dextran with High Ion Transport Properties for EDLC Application DOI: 10.3390/ijms20133369 -
Carbohydrate confidence 1.0
“cm-1 cm-1, cm-1, and 944.61 are typical for carbohydrates, and the bands at 1632.53 1553.51 and and 944.61 cm-1 are typical for carbohydrates, and the bands at 1632.53 cm-1, 1553.51 cm-1, and 1320.33 cm-1 cm-1 1320.33 can be assigned to ami”
Efficient Degradation of High-Molecular-Weight Hyaluronic Acid by a Combination of Ultrasound, Hydrogen Peroxide, and Copper Ion DOI: 10.3390/molecules24030617 -
Amide confidence 1.0
“-C-H stretching -C=O 1656 stretching (Amide I) -C=O 1620 stretching (Amide I) 1554 C-N-H deformation (Amide II) 1375”
Metal and Phosphate Ions Show Remarkable Influence on the Biomass Production and Lipid Accumulation in Oleaginous Mucor circinelloides DOI: 10.3390/jof6040260 -
C c single bond confidence 1.0
“cm(cid:2)1, and a positive C-C positive amide II band at 1554 cm(cid:2)1.”
Time-Resolved Microspectroscopy on a Single Crystal of Bacteriorhodopsin Reveals Lattice-Induced Differences in the Photocycle Kinetics DOI: 10.1529/biophysj.106.083345
Have a spectrum with this band?
Upload your FTIR spectrum and get a full interpretation report — peak assignments with literature citations, library matches, and a literature-backed analysis — in seconds.