What absorbs at 1598 cm⁻¹ in an FTIR spectrum?
A band near 1598 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 1598 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 |
|---|---|---|---|
| N h | 13 | 12 | 1.0 |
| Aromatic ring | 7 | 7 | 1.0 |
| Carboxyl (COOH) | 5 | 5 | 1.0 |
| Ring structure | 4 | 4 | 1.0 |
| Methoxy (OCH3) | 3 | 3 | 1.0 |
| Methacrylate | 3 | 3 | 1.0 |
| C-O single bond | 3 | 3 | 1.0 |
| Acetate | 3 | 3 | 1.0 |
| Carbonyl (C=O) | 3 | 3 | 1.0 |
| Alkene (C=C) | 2 | 2 | 1.0 |
| C=n | 2 | 2 | 1.0 |
| C c single bond | 2 | 2 | 1.0 |
| Water (H2O) | 2 | 2 | 1.0 |
| Lignin | 2 | 2 | 1.0 |
| Alkyl C-H | 2 | 2 | 1.0 |
| Amide | 2 | 2 | 1.0 |
| Secondary amine | 2 | 2 | 1.0 |
| Amine primary | 1 | 1 | 1.0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1.0 |
| Silicon (Si) | 1 | 1 | 1.0 |
| Hydroxyl (O-H) | 1 | 1 | 1.0 |
| Sulfur | 1 | 1 | 1.0 |
| Hydrogen bond | 1 | 1 | 1.0 |
Ranking reflects accumulated literature evidence, not a single fixed rule. Always confirm against your sample context.
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 1598 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
“The glass slidewas then placedinthesample holder with NH 4SCN are the carboxamide at and the amino bands at1598cm-1[[21].”
Synthesis and characterizations of phthaloyl chitosan-based polymer electrolytes DOI: 10.1016/j.jnoncrysol.2012.04.019 -
confidence 1.0
“while the IR peak around 1598 originates from the bending In order to provide a robust explanation for the experimode of the N-H and O-H bonds.”
Hydration of mixed halide perovskites investigated by Fourier transform infrared spectroscopy DOI: 10.1063/1.5087914 -
Hydrogen bond confidence 1.0
“In theFTIRspectraofWFD/SA-PEI,peaksofthe-COO(asymmetric)stretchingvibrationshiftedto1598 Citation: Kim,H.;Purev,O.;Myung, cm-1, and 1395 which could be attributed to the hydrogen-bonding effect of the N-H groups in PEI.”
Kim 等 - 2022 - Removal of Methyl Red from Aqueous Solution Using DOI: 10.3390/ijerph19159030 -
Sulfur confidence 1.0
“The peaks at 1598 and on both with binding energy 168.5eV, which is attributed to sulfur”
Li 和 Mu - 2005 - The electrochemical activity of sulfonic acid ring DOI: 10.1016/j.synthmet.2004.12.015 -
Carbonyl (C=O) confidence 1.0
“Represented C=O asymmetric stretching.”
Ouyang 等 - 2012 - Adsorption of Cu (II) from aqueous single metal so DOI: 10.4028/www.scientific.net/AMR.535-537.1601 -
N h confidence 1.0
“The band at 1598 cm-1 that could form on the surface of each catalyst tested, and is attributed to the asymmetric deformation of NH ((cid:228) as3 increasing temperatures were used to judge the stability of these sites.24,31 (NH 3)) coordin”
Pena 等 - 2004 - Identification of surface species on titania-suppo DOI: 10.1021/jp0313122 -
Hydroxyl (O-H) confidence 1.0
“The FTIR spectrum shows two peaks at Dilutedmagneticsemiconductor(DMS) 1598cm-1 ∼3428 and which are attributed to O-H stretching and H-O-H bending vibration.”
EPR and photoluminescence studies of ZnO:Mn nanophosphors prepared by solution combustion route DOI: 10.1016/j.saa.2011.03.014 -
Carboxyl (COOH) confidence 1.0
“At these pH values, the amine group is protonated and differentiates the two vibrations.50 as(COO-) cm-1 carboxylate The ν of -carboxylate peak at 1598 gets broadened as a as(COO-) cm-1 result of H-bonding with the amine group, and another”
pH-Dependent Adsorption of α-Amino Acids, Lysine, Glutamic Acid, Serine and Glycine, on TiO2 Nanoparticle Surfaces DOI: 10.1016/j.jcis.2019.06.086
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