What absorbs at 869 cm⁻¹ in an FTIR spectrum?

Quick answer

A band near 869 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.

可能性のある官能基アサイン

ランキングは蓄積された文献証拠を反映しており、単一の権威あるルールではありません。常にサンプルのコンテキストと照合して確認してください。

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 869 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.

これらのアサインの根拠となる文献

• Alkyl C-H 信頼度 1.0

  “869cm-1 films C-H and at in PAni doped may be due to out of plane cm-1 film bending.”

  Influence of polyaniline doping concentration in (Bi0.5Sb0.5)2S3 thin polycrystalline films on structural, electrical and optical properties DOI: 10.1016/j.jnoncrysol.2010.03.012
• Metal oxygen 信頼度 1.0

  “Another peak at cm-1 869 in the BFD spectrum, can occur from the Al-O stretching in AlO4 tetrahedra of aluminate, or from symmetric Si-O-Si stretching in SiO4 tetrahedra of alite (Ghosh and Handoo, 1980;”

  Micro-characterization of Dust and Materials of Dust Origin at a Cement Industry Located in Bangladesh DOI: 10.4209/aaqr.220109
• Aromatic ring 信頼度 1.0

  “The presence of both bands together with the band at 869 due to the aromatic C-H out-of-plane bending vibrations, confirms the presence of a significant amount of hydrolysable tannins in the eucalyptus bark extract.”

  Santos 等 - 2023 - Forest by-Product Valorization Pilot-Scale Pinus DOI: 10.3390/f14050895
• Hydroxyl (O-H) 信頼度 1.0

  “literatures10,17 cm-1 According to peak at 1065 is assigned to BRB-PMo hybrid was synthesized by addition of 0.05 12 cm-1 inner P-O a-Mo bond, peak at 790 to Mo-O d-Mo bridges, g/mL aqueous solution of butylrhodamine B dropwise to a cm-1 cm”

  Zeng 等 - 2013 - Electrochemical and Fluorescent Investigation of I DOI: 10.14233/ajchem.2013.14039
• Acetate 信頼度 1.0

  “The following bands belong to PCL: C=O stretching (1724, 1182 valence cm-1), cm-1) C-O-C vibrations (869, 1043, and 1109 C=C stretching (1286 [28,33].”

  Polymer Composite Materials Based on Polylactide with a Shape Memory Effect for “Self-Fitting” Bone Implants DOI: 10.3390/polym13142367
• 信頼度 0.9

  “Explicit assignment: 'deformation bands 869 cm-1 ... originating from PA'.”

  Characterization of New Polymer Material of Amino–Cyclodextrin and Sodium Alginate for Environmental Purposes DOI: 10.3390/membranes13040447
• 信頼度 0.8

  “Micro-window centered at 869 cm-1 for HCl retrieval.”

  Retrieval of Stratospheric HNO3 and HCl Based on Ground-Based High-Resolution Fourier Transform Spectroscopy DOI: 10.3390/rs13112159