What absorbs at 1099 cm⁻¹ in an FTIR spectrum?

Quick answer

A band near 1099 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.

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 1099 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

• Acetate confidence 1.0

  “The IR spectrowith several modes with a band centered at 1099 C-O 950-1180 cm-1 scopicdifferencescalculatedwiththeseDFTmodelsverify stretching component in the region andtheO-Hstretchingmodecenteredat3352cm-1.The the experimental difference”

  Brewer 等 - 2004 - Infrared detection of a phenylboronic acid termina DOI: 10.1021/la035037m
• C-O single bond confidence 1.0

  “The pinning [42,43] surface hydroxyl group (-OH) weak 1633 [44] asymmetric stretching band of C-O weak 2341 force of the grain boundary is a non-negligible factor affecting the Ms [45] C-O-C stretching vibration medium 1099”

  Low-temperature synthesis of Sr2FeMoO6 double perovskite; structure, morphology, and magnetic properties DOI: 10.1016/j.ceramint.2020.03.264
• Ammonium confidence 1.0

  “4 cm-1 The peak appeared at 1099 may be attributed to the SO2cm-1 of (NH 4) 2SO and that at 1026 to the Si-O or”

  Parida 等 - 2004 - Studies on manganese-nodule leached residues - 1. DOI: 10.1016/j.jcis.2004.04.057
• confidence 1.0

  “cm-1 with Si-OH stretching vibration at wave numbers around 3415.93-3383.14 and Si-O-Si stretching vibration from siloxane groups at wave number 1099.43 cm-1.”

  Wahyuningsih 等 - 2021 - Characteristics of Silica Nanoparticles from Rice DOI: 10.5614/j.eng.technol.sci.2021.53.4.3
• C c single bond confidence 1.0

  “cm-1 1099 The peak at 1099 is assigned to C-C stretch.”

  Wong 等 - 2018 - Cobalt Deposition in Graphene Quantum Dot Bath El DOI: 10.1149/2.0041807jes
• Acetate confidence 1.0

  “cm-1 carbonyl stretching vibration (C=O) which occurred at 1720 The peak at 1099 cm-1 corresponded to C-O-C stretching vibration and the peaks at 2932 and 2974 are assigned to sp3 -CH bond respectively.”

  Influence of the synthesis parameters on the properties of natural rubber grafted poly-3-hydroxybutyrate (acte de congrès - 10 pages) DOI: 10.1088/1757-899X/509/1/012024
• Water (H2O) confidence 1.0

  “cm-1 absorbed water molecule on the silica The sharp peak band at 1099 is due to the Si-O-Si asymmetric cm-1 stretching vibration, whereas the band at 803 has been assigned to the network Si-O-Si symmetric bending”

  Asmi 等 - 2016 - Synthesis and Characterisation of Composite based DOI: 10.1063/1.4945463
• confidence 1.0

  “The absorptions peak at 1099 can denote the Si-O stretching modes of silica and silicates.”

  The Physico-Chemical and Mineralogical Characterization of Mg-Rich Synthetic Gypsum Produced in a Rare Earth Refining Plant DOI: 10.3390/su13094840