What absorbs at 3080 cm⁻¹ in an FTIR spectrum?

Quick answer

A band near 3080 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 3080 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

  “Results and discussion of the aromatic compounds have nearly four Infrared peaks in the 3080-3010cm-1 region due to ring C-H stretching bonds [12,13].”

  Nagabalalsubramanian 等 - 2009 - A scaled quantum mechanical approach of vibrationa DOI: 10.1016/j.saa.2009.10.002
• Ring structure confidence 1.0

  “As predicted in the earlier refin the region 3080-3010cm-1 peaks in the region due to ring C H stretching erences, in our title compound also the prominent peaks at 1600, 1590,1495,1450cm-1 bonds [11,12].”

  Nagabalasubramanian 等 - 2009 - FTIR and FT Raman spectra, vibrational assignments DOI: 10.1016/j.saa.2009.02.044
• confidence 1.0

  “cm-1 and wide bands at 3080 and 3380 The absorbance bands at 480, 605 and 735 are assigned to Al-O absorption18.”

  Heteroployacid on the composite of boehmite and polyionic liquid as a catalyst for alcohol oxidation and tandem alcohol oxidation Knoevenagel condensation reactions DOI: 10.1038/s41598-022-20699-2
• Alkyl C-H confidence 1.0

  “LLM confirmed rule peak-group candidate”

  Arbab Solimani 等 - 2023 - Carboxymethyl Chitosan-Functionalized Polyaniline DOI: 10.1007/s12010-023-04526-6
• confidence 1.0

  “bonded N-H stretching (3080 and OH/NH groups (3400-3100 A shoulder at cm-1 1429 represents the CH scissor vibration.”

  Comparative Characterization of Hot-Pressed Polyamide 11 and 12: Mechanical, Thermal and Durability Properties DOI: 10.3390/polym13203553
• N h confidence 1.0

  “AmideBhasthebandbetween3080and3070cm-1 andisattributedtothesecondFermiresonance, ν(NH) which is between the valence vibration and the end of amide II.”

  The Comparative Study of the State of Conservation of Two Medieval Documents on Parchment from Different Historical Periods DOI: 10.3390/ma13214766
• Alkyl C-H confidence 1.0

  “Attribution Attribution -C-H stretching vibration of carbon-carbondoublebondin Stretching vibration of CC main 3080”

  Chen 等 - 2013 - Fourier Transform Infrared Spectral Analysis of Po DOI: 10.1155/2013/937284
• Alkene (C=C) confidence 1.0

  “The olefinic stretching CH3 symetric bending sp3 cm-1 =C-H C H stretching µm) asymmetric stretching at 3080 (3.3 is signif0.02 icantly small.”

  Hodoroaba 等 - 2018 - Carbon 'fluffy' aggregates produced by helium-hydr DOI: 10.18434/T4D303