What absorbs at 1560 cm⁻¹ in an FTIR spectrum?
A band near 1560 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 1560 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 | 35 | 32 | 1.0 |
| Carboxyl (COOH) | 23 | 23 | 1.0 |
| N h | 22 | 19 | 1.0 |
| Acetate | 15 | 14 | 1.0 |
| Methacrylate | 13 | 13 | 1.0 |
| Alkene (C=C) | 13 | 13 | 1.0 |
| Carbonyl (C=O) | 12 | 12 | 1.0 |
| Secondary amine | 11 | 9 | 1.0 |
| Ketone | 8 | 8 | 1.0 |
| Ester | 8 | 8 | 1.0 |
| Aromatic ring | 7 | 5 | 1.0 |
| C n single bond | 6 | 6 | 1.0 |
| Methoxy (OCH3) | 6 | 6 | 1.0 |
| Alkyl C-H | 6 | 5 | 1.0 |
| C-O single bond | 5 | 5 | 1.0 |
| Protein | 5 | 5 | 1.0 |
| Hydroxyl (O-H) | 4 | 4 | 1.0 |
| Water (H2O) | 3 | 3 | 1.0 |
| Amine primary | 3 | 1 | 1.0 |
| Carbonate | 2 | 2 | 1.0 |
| C c single bond | 2 | 2 | 1.0 |
| Nitrogen heterocycle | 2 | 2 | 1.0 |
| Amino acid | 2 | 2 | 1.0 |
| N-O bond | 1 | 1 | 1.0 |
| Methyl | 1 | 1 | 1.0 |
| Chitosan | 1 | 1 | 1.0 |
| C=n | 1 | 1 | 1.0 |
| Fatty acid | 1 | 1 | 1.0 |
| Nitrate | 1 | 0 | 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 |
|---|---|---|---|
| alginate | 1560, 1100, 1715 | Acetate, Carboxyl (COOH), Amide | 1 |
| dentin | 1560, 575, 1740 | Amide, Acetate, 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 1560 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
-
Fatty acid confidence 1.0
“Findings COOcm-1 At low fatty acids concentration, the asymmetric stretching vibration of peaks at 1560 while, at higher concentration, this infrared band converts into a doublet peaking at 1535 and cm-1.”
Adsorption mechanisms of fatty acids on fluorite unraveled by infrared spectroscopy and first-principles calculations DOI: 10.1016/j.jcis.2020.09.062 -
Carboxyl (COOH) confidence 1.0
“LLM confirmed rule peak-group candidate”
Gandolfi 等 - 2011 - Biomimetic remineralization of human dentin using DOI: 10.1016/j.dental.2011.07.007 -
Carboxyl (COOH) confidence 1.0
“cm-1 cm-1 In addition this, for the AlgS-Pb bands are observed at 1560 and 1388 associated with the vibrations of group carboxylate, which would indicate the participation of this in RIPT”
Huamani-Palomino 等 - 2019 - Chemical modification of alginate with cysteine an DOI: 10.1016/j.ijbiomac.2018.09.096 -
confidence 1.0
“In both species, a new icant changes were mainly in functional groups/structure peakappearedbetween1560and1590cm-1intheATR-FTIR corresponding to amino acids and proteins in the region cm-1 1560-1590 spectra as the diatoms were cultured away”
La Vars 等 - 2013 - Si-29{H-1} CP-MAS NMR comparison and ATR-FTIR spec DOI: 10.1007/s00216-013-6746-z -
Acetate confidence 1.0
“The FTIR S.-Y.Linetal./JournalofPharmaceuticalandBiomedicalAnalysis53 (2010) 799-803 801 spectrumofintactLORisalsodisplayedinFig.2.SeveralcharacteristicIRabsorptionbandsandtheirassignmentsofLORareshownas 1703cm-1 1474cm-1 follows: (C O of e”
Curve-fitting FTIR studies of loratadine/hydroxypropyl-β-cyclodextrin inclusion complex induced by co-grinding process DOI: 10.1016/j.jpba.2010.06.010 -
confidence 1.0
“From the figure the carbonyl and amine bands are located 1560cm(cid:1)1 at 1643 and respectively.”
Majid 和 Arof - 2008 - FTIR studies of chitosan-orthophosphoric acid-ammo DOI: 10.1080/15421400801904286 -
Amide confidence 1.0
“The band at 1560 assigned to a-elastin, ture in the strand form take place in the final stage of the amide II, appearing in the synchronous spectrum of thermal denaturation process.”
Structural analysis of some soluble elastins by means of FTIR and 2D IR correlation spectroscopy DOI: 10.1002/bip.21524 -
Acetate confidence 1.0
“cm-1 NHS were responsible for the peak appearance at 1270 The prominent peak observed at 1560 and cm-1 = 1540 indicates the strong C O and N-H deformation in the chemical structure of EDC and NHS when it = has reacted with APTES modified al”
Aluminosilicate Nanocomposite on Genosensor: A Prospective Voltammetry Platform for Epidermal Growth Factor Receptor Mutant Analysis in Non-small Cell Lung Cancer DOI: 10.1038/s41598-019-53573-9
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