What absorbs at 1506 cm⁻¹ in an FTIR spectrum?

Quick answer

A band near 1506 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

Ranking reflects accumulated literature evidence, not a single fixed rule. Always confirm against your sample context.

Possible materials

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 1506 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

  “LLM confirmed rule peak-group candidate”

  Mechanism and Kinetics of Curing of Diglycidyl Ether of Bisphenol A (DGEBA) Resin by Chitosan DOI: 10.1002/pen.24463
• C c single bond confidence 1.0

  “~1725 Aromatic Ring C=C Stretching ~1605 Aromatic Ring C-C Stretching ~1506 Stretching of Symmetrical aromatic C-O-C”

  Degradation Performance Investigation of Hydrothermally Stressed Epoxy Micro and Nanocomposites for High Voltage Insulation DOI: 10.3390/polym14061094
• C c single bond confidence 1.0

  “The www.worldscientific.com cm-1 peak at 1506 represents a C C stretching vibration in the benzenoid ring.”

  A facile synthesis of poly(aniline-co-o-bromoaniline) copolymer: Characterization and application as semiconducting material DOI: 10.1142/S0217979216500089
• Lignin confidence 1.0

  “The lignin peak at 1506 594 E.D.”

  Tomak - 2014 - Changes in chemical composition of decayed Scots p DOI: 10.1515/secm-2013-0180
• Aromatic ring confidence 1.0

  “bamboo scrimber samples placed in the north and south region 1506cm-1 was arising from aromatic Since the absorption peak at for six years weathering period, respectively.”

  Study of the long-term degradation behavior of bamboo scrimber under natural weathering DOI: 10.1038/s41529-022-00273-x
• C c single bond confidence 1.0

  “The absorption wavenumber of 1601 and 1480 the excellent homogeneity and low roughness PEI[ethacm-1 is due to the C-C stretch in the aroband at 1506 nol]/CNER[chloroform] (Figure 1(e)) was selected for ring.20 The CH 2-O-CH bending mode of”

  Development of layer‐by‐layer assembled thin coatings on aluminium alloy AA2024‐T3 for high resolution studies of local corrosion processes DOI: 10.1002/app.49826
• Aromatic ring confidence 1.0

  “However, there were substantial cm-1 increases in the intensities of the peaks at 1595 (C=C aromatic skeletal vibration), cm-1 cm-1 1506 (C=C aromatic skeletal stretching vibration), 1453 (C-H deformation), cm-1”

  Altuntas 等 - 2017 - Biodegradation Properties of Wood-plastic Composit DOI: 10.1002/app.24358
• Carbonate confidence 1.0

  “Poorly crystalline powder displayed an A 2 cm-1) carbonate peak (at 1506 overlapping a cm-1), 32Fig 5.”

  Brangule 等 - 2015 - Importance of FTIR Spectra Deconvolution for the A DOI: 10.1088/1757-899X/77/1/012027