What absorbs at 1544 cm⁻¹ in an FTIR spectrum?
A band near 1544 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 1544 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 | 33 | 28 | 1.0 |
| N h | 10 | 10 | 1.0 |
| Secondary amine | 6 | 6 | 1.0 |
| C n single bond | 6 | 6 | 1.0 |
| Carboxyl (COOH) | 5 | 5 | 1.0 |
| Protein | 4 | 3 | 1.0 |
| Methacrylate | 3 | 3 | 1.0 |
| Acetate | 3 | 3 | 1.0 |
| Alkyl C-H | 3 | 3 | 1.0 |
| Carbonyl (C=O) | 3 | 2 | 1.0 |
| Alkene (C=C) | 2 | 2 | 1.0 |
| Aromatic ring | 2 | 2 | 1.0 |
| Methoxy (OCH3) | 2 | 2 | 1.0 |
| C-O single bond | 2 | 2 | 1.0 |
| Ketone | 2 | 2 | 1.0 |
| Ester | 2 | 2 | 1.0 |
| Nitrogen heterocycle | 2 | 1 | 1.0 |
| Protein beta sheet | 1 | 1 | 1.0 |
| Protein alpha helix | 1 | 1 | 1.0 |
| Lipid | 1 | 1 | 1.0 |
| Chitosan | 1 | 1 | 1.0 |
| C c single bond | 1 | 1 | 1.0 |
| Bromine | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Metal oxygen | 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 |
|---|---|---|---|
| chitosan | 1544, 1650, 1655 | Amide, N h | 1 |
| polypyrrole | 1544, 1700, 400 | Amide, Secondary amine, C n single bond | 1 |
| PPy | 1544, 1043, 910 | Secondary amine, C n single bond, Amide | 1 |
| TiO2 nanoparticles | 1544, 1700, 455 | N h | 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 1544 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
-
confidence 1.0
“A peak in XRD patterns 18.8◦ cm-1 cm-1 2(cid:2) was observed around of related to PPy structure, and the peaks at 1544 and 579 in Keywords: FTIR spectra were assigned to stretching vibration of N H bond and Zn O bond, respectively.”
Structural and electrochemical study of polypyrrole/ZnO nanocomposites coating on nickel sheet synthesized by electrochemical method DOI: 10.1016/j.synthmet.2012.12.013 -
Amide confidence 1.0
“Characteristic signals for proteins were detected at 1544 cm-1 and 1648 and are attributed to amide II and amide I vibrations, respectively.”
Depciuch 和 Parlinska-Wojtan - 2018 - Comparing dried and liquid blood serum samples of DOI: 10.1016/j.jpba.2017.11.074 -
Acetate confidence 1.0
“From FTIR spectra, the sharp cm-1 cm-1 peaks at 1544 and 1389 attributed to the C=O and C-O bonds, respectively, and could be due to bond formation between Mn and oxygen in C=O, and C-O in PDA.”
Bio-inspired metastable intermolecular nanothermite composite based on Manganese dioxide/Polydopamine/Aluminium DOI: 10.1007/s10854-021-05582-6 -
Amide confidence 1.0
“3308cm(cid:1)1 1664cm(cid:1)1 NAH C@O Jesús, Talens, and Chiralt (2010) for soy protein isolate-based films (amide-A, stretching), (amide-I, 1544cm(cid:1)1 1451cm(cid:1)1 NAH containingcinnamonessentialoil.Theseauthorsindicatedthatthe stret”
Development of bioactive fish gelatin/chitosan nanoparticles composite films with antimicrobial properties DOI: 10.1016/j.foodchem.2015.09.004 -
Amide confidence 1.0
“Peaks at 3294 (Amide A), 3060 (Amide B), 2871 (CH 3 1544cm-1 symmetric stretching), 1653 (Amide I) and The intensity or area of a particular FTIR absorption”
Igci 等 - 2017 - Application of Fourier transform infrared spectros DOI: 10.17219/acem/65784 -
confidence 1.0
“The peak at 1544 corresponds to the bending vibrations of N-H bond and 41”
Kaur 等 - 2019 - Expanding horizon green synthesis of TiO2 nanopar DOI: 10.1088/2053-1591/ab2ec5 -
Amide confidence 1.0
“Surimi proteins in dry weight Generally, the peaks mainly mainly consists consists of of cm-1) cm-1) in amide I absorption bands (~1655 and amide II (~ absorption absorption bands bands (~1544 (~1544 cm”
Rapid discrimination of three marine fish surimi by Tri-step infrared spectroscopy combined with Principle Component Regression DOI: 10.1016/j.saa.2015.04.116 -
Aromatic ring confidence 1.0
“The peak at 1544.08 means aromatic ring vibration [32,39].”
Mahardiani 等 - 2022 - Nanofiber Fabrication from Palm Fiber Waste for Su DOI: 10.48317/IMIST.PRSM/morjchem-v10i2.32648
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