What absorbs at 508 cm⁻¹ in an FTIR spectrum?

Quick answer

A band near 508 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 authoritative 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 508 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

• Alkyl C-H confidence 1.0

  “indica by leaf extract were due to the C-H medium bending and the weak band at 508 from the FTIR it was inferred that the bio-organics such as the flavonoids, alkaloids and steroids phytoconstituents from the leaves served as a strong cappi”

  Krishnan 等 - 2020 - Leaf Extract ofDillenia indicaas a Source of Selen DOI: 10.3390/coatings10070626
• Borate confidence 1.0

  “While the peak at 1410 is for B-N and that at 799 for cm-1 B-N-B vibrations, sharp peak at 508 presents bending vibration of O-B-O.”

  Kumar 等 - 2016 - Emergence of fluorescence in boron nitride nanofla DOI: 10.1039/C6RA05288F.
• Alkene (C=C) confidence 1.0

  “cm-1 cm-1 specifically the peak at 1,727 arising from the carbonyl stretching, whereas the peak at 1,508 cm-1 cm-1 associated with the C=C stretching of the aromatic rings.”

  Incorporation of Hyperbranched Supramolecules into Nafion Ionic Domains via Impregnation and In-Situ Photopolymerization DOI: 10.3390/polym3042018
• Ring structure confidence 1.0

  “Feldspar Raman bands (Figure 11b) correspond to plagioclase and possibly to albite Feldspar Raman bands (Figure 11b) correspond to plagioclase and possibly to albite with the Raman peaks at 292, 479 and 508 cm-1 related to SiO ring vibratio”

  Non-Destructive Study of Egyptian Emeralds Preserved in the Collection of the Museum of the Ecole des Mines DOI: 10.3390/min13020158
• Acetate confidence 1.0

  “Amore direct proof comes from the two new bands in C-O stretching 508 PETROVI],NIKOLI]andMARKOVI] cm-1 region: at 1202.5 (weak) and 1122.5 (very strong) for Zn-Chl, and at 1202.3 cm-1 (weak) and 1118.8 (very strong) for Cu-Chl (Table I);”

  Petrovic 等 - 2006 - In vitro complexes of copper and zinc with chlorop DOI: 10.2298/JSC0605501P
• Aromatic ring confidence 1.0

  “et al., 2019) for high compression forces and anisotropic fiber (Figure 3F) Some bands in the PC1 loading point to a change (Gibson, arrangement for high tensile strength respectively in aromatic components (e.g., aromatic skeletal vibratio”

  From the Soft to the Hard: Changes in Microchemistry During Cell Wall Maturation of Walnut Shells DOI: 10.3389/fpls.2020.00466