What absorbs at 942 cm⁻¹ in an FTIR spectrum?

Quick answer

A band near 942 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 942 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

• Ring structure confidence 1.0

  “Raman Spectra and XPS analysis cm-1 The Figure 2.c.i the Raman spectrum of PPy indicates the ring deformation at 942 cm-1.”

  Highly Biological Active Antibiofilm, Anticancer and Osteoblast Adhesion Efficacy from MWCNT/PPy/Pd nanocomposite DOI: 10.1016/j.apsusc.2017.10.142
• Silanol (Si-OH) confidence 1.0

  “2 cm-1 were found at around 1078 ascribed to Si-O-Si (asymmetric stretching vibration) and cm-1 around 942 ascribed to silanol (Si-OH) groups (bending vibration).”

  Study of Polyvinyl Alcohol-SiO2 Nanoparticles Polymeric Membrane in Wastewater Treatment Containing Zinc Ions DOI: 10.3390/polym13111875
• N h confidence 1.0

  “4) 2H 2(PO 4) 2O), however, can exist exhibiting vibra- (NH over the spectra range between 650 and 4000 The ATRcm-1 43reflection due to the PO stretching tional peaks close to 942 FTIR internal element (IRE, Pike Technologies) that was band”

  Kirinovic 等 - 2017 - Spectroscopic and Microscopic Identification of th DOI: 10.1021/acssuschemeng.6b02327
• Alkyl C-H confidence 1.0

  “The peak at 942 observed in the Tylose MH 50 composites film control film could be associated with C-H monosubstituted out of plane bending for C-H.”

  Mustary 等 - 2023 - Synthesis and Characterization of Biocomposite Fil DOI: 10.33263/BRIAC133.274
• Alkyl C-H confidence 1.0

  “1634 C = C stretching symmetric stretching 1384 1375 1373 CH 2 C-O 1038 1017 1018 1020 stretching C-H 942 945 945 944 out-of-plane bending”

  Premalatha 等 - 2017 - Tamarind seed polysaccharide (TSP)-based Li-ion co DOI: 10.1007/s11581-017-1989-x
• Alkyl C-H confidence 1.0

  “a weak ~942 cm-1, band due to the C-H out-of-plane bending motion;”

  Identification of Colourants and Varnishes in a 14th Century Decorated Wood-Carved Door of the Dionysiou Monastery in Mount Athos DOI: 10.3390/coatings11091087
• Silicon (Si) confidence 1.0

  “symmetric and symmetric ν(Si-O-C) modes at 1077 and 942 cm-1, respectively [58,59].”

  Thiolated Janus Silsesquioxane Tetrapod: New Precursors for Functional Materials DOI: 10.3390/molecules27227680
• C c single bond confidence 1.0

  “942 (C-C out-of-plane vibration);”

  High-voltage and long-lasting aqueous chlorine-ion battery by virtue of “water-in-salt” electrolyte DOI: 10.1016/j.isci.