What absorbs at 1594 cm⁻¹ in an FTIR spectrum?
A band near 1594 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 1594 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 |
|---|---|---|---|
| Methacrylate | 9 | 9 | 1.0 |
| Carboxyl (COOH) | 9 | 9 | 1.0 |
| Acetate | 9 | 9 | 1.0 |
| Amide | 8 | 8 | 1.0 |
| Aromatic ring | 6 | 6 | 1.0 |
| Carbonyl (C=O) | 6 | 5 | 1.0 |
| Alkyl C-H | 5 | 5 | 1.0 |
| C c single bond | 5 | 5 | 1.0 |
| Methoxy (OCH3) | 5 | 5 | 1.0 |
| Alkene (C=C) | 5 | 5 | 1.0 |
| C-O single bond | 5 | 5 | 1.0 |
| Ketone | 4 | 4 | 1.0 |
| Ester | 4 | 4 | 1.0 |
| N h | 3 | 3 | 1.0 |
| Hydroxyl (O-H) | 3 | 3 | 1.0 |
| C=n | 3 | 3 | 1.0 |
| Lignin | 2 | 2 | 1.0 |
| Hydrogen bond | 1 | 1 | 1.0 |
| Nitrogen heterocycle | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Methyl | 1 | 1 | 1.0 |
| Secondary amine | 1 | 1 | 1.0 |
| Amine primary | 1 | 1 | 1.0 |
| N-O bond | 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 | 1594, 1565, 1570 | Amide, Methacrylate, Acetate | 1 |
| silver nanoparticles | 1594, 1636, 1631 | Methacrylate, Acetate, 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 1594 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
-
Aromatic ring confidence 1.0
“An CAC at 1519 (aromatic stretching) reveals the disappearance of cm-1 additional negative-going broad band can be observed at benzenoid rings and the less intense band at 1594 is assigned to cm-1, 1592 which partially overlaps the uncompen”
Revisiting the Redox Transitions of Polyaniline. Semiquantitative Interpretation of Electrochemically Induced IR Bands DOI: 10.1016/j.jelechem.2021.115593 -
Aromatic ring confidence 1.0
“santalinus only at 1594 cm-1, 1205 cm-1, 1155 cm-1 and 836 cm-1, corresponding to the stretching vibration of carbon atoms in the aromatic framework, C-O-C stretching vibration in extractives, C-O-”
Jin 等 - 2022 - Rapid Identification for the Pterocarpus Bracelet DOI: 10.3390/molecules27154793 -
C c single bond confidence 1.0
“- - - C O stretching vibration of carboxylic acid and ester in hemicellulose 1738 Absorbed water 1646 - - - - 1593 1592 1589 Aromatic C C vibration 1594 1592 Lignin component (Rosa et al., 2012) 1505”
Kasyapi 等 - 2013 - Bionanowhiskers from jute Preparation and charact DOI: 10.1016/j.carbpol.2012.10.021 -
Amide confidence 1.0
“Probe (labeled) seen 2 cm21, 1326 to 1356 and total protein (amide I band) 1594 passing successfully through the glottis.”
Compositional Assessment of Human Tracheal Cartilage by Infrared Spectroscopy DOI: 10.1177/0194599817752310 -
C c single bond confidence 1.0
“of vibrational bands were at 1594, 1082, and 474 cm-1, The main position band was at 1594 corresponding C-C to the stretching vibration and the peaks were at C-H cm-1, 1082 attributed to the stretching vibration, cm-1, whereas weak peak was”
Logaranjan 等 - 2016 - Shapeand Size-Controlled Synthesis of Silver Nan DOI: 10.1186/s11671-016-1725-x -
Acetate confidence 1.0
“carboxylic acid salts at 1594.23 and 1552.76 In BA, the neutral carboxylic group (-COOH) a group of carboxylic acids of BA at 1686.82 cm-1 that were not found, replaced by the band cm-1 had a strong carbonyl (C=O) with stretching at a peak”
A Novel Desloratadine-Benzoic Acid Co-Amorphous Solid: Preparation, Characterization, and Stability Evaluation DOI: 10.3390/pharmaceutics10030085 -
Alkene (C=C) confidence 1.0
“The 2 cm-1, cm-1, cm-1 C=C stretching vibrations at 1594 cm-1, 1504 cm-1, and 1460 cm-1 of lignin and -CHskeletal C=C stretching vibrations at 1594 1504 and 1460 of lignin and cm-1 stretching vibrations at 1425 cm-1 are all present in raw-K”
Blaquera 等 - 2023 - Oil Adsorption Kinetics of Calcium Stearate-Coated DOI: 10.3390/polym15020452 -
Aromatic ring confidence 1.0
“cm-1, t Aromatic ring C=C-C stretching vibrations located at 1594 aliphatic C-H”
Polymer-Assisted Aripiprazole-Adipic Acid Cocrystals Produced by Hot Melt Extrusion Techniques DOI: 10.1021/acs.cgd.0c00020.
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