What absorbs at 2854 cm⁻¹ in an FTIR spectrum?

Quick answer

A band near 2854 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 2854 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

  “The two peaks 2854cm(cid:1)1 cm(cid:1)1 at and 2922 correspond to the symmetric Vs (CH 2) and asymmetric Vas (CH 2) vibrations, while no significant peak is found in graphite.”

  Graphite oxide-incorporated CeP2O7/BPO4 solid composite electrolyte for high-temperature proton exchange membrane fuel cells DOI: 10.1016/j.fuel.2016.03.089
• Alkyl C-H confidence 1.0

  “Further, the negative influence of PC2 loadings shown at 2926 (asympartly supportive to differentiate roots (samples) due to the variations of possible molecm-1 metric CH stretching) and 2854 (symmetric CH stretching) clearly differentiated”

  Specific Mycoparasite-Fusarium Graminearum Molecular Signatures in Germinating Seeds Disabled Fusarium Head Blight Pathogen’s Infection DOI: 10.3390/ijms22052461
• Fatty acid confidence 1.0

  “The increase in peak intensity at 2854 is due to under cm(cid:1)1 the abundance of long-chain fatty acids and that at 3006 28 Component analysis of CSB”

  Influence of flaxseed flour as a partial replacement for wheat flour on the characteristics of Chinese steamed bread DOI: 10.1039/d0ra05742h
• Alkyl C-H confidence 1.0

  “Explicit assignment in text.”

  Mansour 等 - 2017 - Elucidation of penetration enhancement mechanism o DOI: 10.1016/j.saa.2017.05.026
• Alkene (C=C) confidence 1.0

  “[23] cm-1 ducts was not evident because characteristic frequencies around those used the band at ~2854 (symmetric stretching vibration of the cm-1), related to the hydroperoxide moiety (~3530 the -cis olefinic functional group) without any”

  Getting inside on virgin olive oil (VOO) photooxidation kinetics through combined generalized 2D correlation analysis and moving window 2D correlation analysis of ATR-FTIR spectra DOI: 10.1016/j.talanta.2020.120917
• Alkyl C-H confidence 1.0

  “Thepresentstudyshowsthesynthesisofmagnetitenanoparticlesbyco-precipitationmethodinthree steps.ThestepsinvolvetheprecipitationofFe 3O 4nanoparticlesfollowedbylayerbylayer functionalizationwithsilicaandtetraethoxy(octadyl)silane(C18).Theprepa”

  High yield, facile aqueous synthesis and characterization of C18 functionalized iron oxide nanoparticles DOI: 10.1088/2053-1591/2/4/045014
• Hydroxyl (O-H) confidence 1.0

  “cm-1 cm-1 and remaining OH groups at 3316 The C-H stretches was observed at 2926 and 2854 cm-1, cm-1 cm-1 followed by peaks at 1511 1213 and 1068 which indicates the urethane linkages of N-”

  Norshahli 等 - 2018 - Mechanical Properties of Palm Oil Polyol based Pol DOI: 10.1088/1742-6596/1082/1/012041
• Hydroxyl (O-H) confidence 1.0

  “The stretching of OH groups was associated with the band at 2854 cm-1 [53].”

  Green Synthesis of Silver Nanoparticles for Preparation of Gelatin Films with Antimicrobial Activity DOI: 10.3390/polym14173453