What absorbs at 841 cm⁻¹ in an FTIR spectrum?

Quick answer

A band near 841 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 841 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

• C c single bond 信頼度 1.0

  “The ~841 band is assigned to tained two-dimensional pattern employing a data processing software, C-C the vibration coupling of stretching, CH2 rocking, and CH3 rocking”

  Probing the difference of crystalline modifications and structural disorder of isotactic polypropylene via high-resolution FTIR spectroscopy DOI: 10.1016/j.polymer.2021.123722
• Nucleic acid 信頼度 1.0

  “The presence of B-DNA and Z-DNA bands at 841 and 815 suggested that only the Z-DNA form is more pronounced in melanoma, whereas both DNA forms were detected in BCC [92].”

  Vibrational Spectroscopy Fingerprinting in Medicine: from Molecular to Clinical Practice DOI: 10.3390/ma12182884
• C c single bond 信頼度 1.0

  “at 841 cm-1 and 1168 cm-1,corresponding to C-C isopropyl stretching;”

  From Waste to Potential Reuse: Mixtures of Polypropylene/Recycled Copolymer Polypropylene from Industrial Containers: Seeking Sustainable Materials DOI: 10.3390/su14116509
• Acetate 信頼度 1.0

  “In κ-carrageenan, the vibrations from 841, 921 and 1035 cm-1 and 1035 could be assigned to -C-O-SO 3stretching vibrations from the galactose-4-sulphate, cm-1 could be assigned to -C-O-SO3stretching vibrations from the galactose-4-sulphate,”

  Croitoru 等 - 2020 - Physically Crosslinked Poly (Vinyl Alcohol)Kappa- DOI: 10.3390/polym12030560
• Carbohydrate 信頼度 1.0

  “The band α-anomer of 841 represents the functional groups of polysaccharides include also the in the pyranose form of sugars.”

  Egyptian Opuntia ficus-indica (OFI) Residues: Recovery and Characterization of Fresh Mucilage from Cladodes DOI: 10.3390/horticulturae9070736
• Carbohydrate 信頼度 1.0

  “Finally, absorptions at 944 cm-1 and 841 cm-1 were assigned to the pyranose ring.”

  Gabriela Chuc-Gamboa 等 - 2021 - Antibacterial Behavior of Chitosan-Sodium Hyaluron DOI: 10.3390/app1103
• Alkene (C=C) 信頼度 1.0

  “A peak at 1228 indicates cm-1 a strong CO bond, and a peak at 841 indicates a bending C=C bond of the alkene.”

  Grgac 等 - 2022 - The Effect of Ultrasonic Treatment on the Binding DOI: 10.3390/ma15020470
• Alkyl C-H 信頼度 1.0

  “rock, C-C stretch 1165 CH bend, CH 3 rock, CH bend 996 CH bend, CH 3 3 rock, C-CH stretch 841 CH 2 3 rock, C-C stretch, C-CH stretch 809 CH 2 2915 CH stretch Polyethylene (PE) (Asensio et al., 2009;”

  Malla-Pradhan 等 - 2022 - Occurrence and Distribution of Microplastics from DOI: 10.1007/s11270-022-05896-z