What absorbs at 442 cm⁻¹ in an FTIR spectrum?

Quick answer

A band near 442 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 442 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

• confidence 1.0

  “It shows two strong characteristic absorption 723.67eV correspond to Fe 2p1/2, these peaks can be attributed to bands at 592 cm-1 and 442 cm-1.”

  Structural and magnetic properties of Gd-Zn substituted M-type Ba-Sr hexaferrites by sol-gel auto-combustion method DOI: 10.1016/j.jallcom.2019.06.348
• confidence 1.0

  “doi: 10.1063/1.4810583 © 2013 AIP Publishing LLC 978-0-7354-1160-9/$30.00 1027 cm-1 Second broad weak absorption peak near 442 may be attributed to bending of Fe-O and Bi-O groups.”

  Singh 等 - 2013 - Synthesis and Optical Properties of Y(3+)Doped BiF DOI: 10.1063/1.4810583
• Metal oxygen confidence 1.0

  “In addition, the spectra of the PLA/hyb nanocomposites show two cm-1 442 that represent the stretching vibrations of Al-O and new weak peaks at 516 and 462 443 bending vibrations of Si-O from the nanohybrid (Zhang et al., 2003;”

  Influence of montmorillonite/carbon nanotube hybrid nanofillers on the properties of poly(lactic acid) DOI: 10.1016/j.clay.2020.105925
• confidence 1.0

  “For molecules, the peak at the 3,442cm-1 composites wavenumber belongs to the amino groups.”

  Song 等 - 2020 - Improved high-temperature damping performance of n DOI: 10.1515/epoly-2020-0054
• Acetate confidence 1.0

  “2 441 stretching vibration respectively, which is suggestive of acyl chain flexibility, whilst the peak at cm-1 442 1732 represents C=O stretching within the ester group on the phospholipids' tail.”

  Weaver 等 - 2022 - Microfluidic-mediated self-assembly of phospholipi DOI: 10.1016/j.ijpharm.2021.121347
• confidence 0.9

  “Explicit assignment in text”

  Guo 等 - 2010 - Micro-Raman and FTIR Spectroscopic Observation on DOI: 10.1021/jp9104147
• confidence 0.8

  “Range 425-442 cm-1 corresponds to octahedral clusters”

  Singhal 等 - 2012 - Magnetic Properties of BaAlFe11O19 Hexaferrite wit DOI: 10.1080/10426914.2011.551961