What absorbs at 635 cm⁻¹ in an FTIR spectrum?

Quick answer

A band near 635 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 635 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

• Hydrogen bond 信頼度 1.0

  “elements are electronegative element capable of forming reaction on compound can be identified from the peak with (1) intramolecular hydrogen bonding with the hydrogen element from cm-1 which represented the stretching weak intensity at 635”

  Synthesis of a novel 1,4‐bis[2‐(5‐thiophen‐2‐yl)‐1‐benzothiophene]‐2,5‐dioctyloxybenzene pentamer for creatinine detection. DOI: 10.1002/ajoc.202100374
• Water (H2O) 信頼度 1.0

  “This decomposition process was intended The peak at 635 was due to the incorporation of CdO due to the removal of moisture, physisorbed and cheminto PVA matrix in the FTIR spectra.”

  Synthesis, Structural, Optical, Electrical and Thermal Studies of Poly(vinyl alcohol)/CdO Nanocomposite Films DOI: 10.1007/s10904-017-0662-1
• Metal oxygen 信頼度 1.0

  “Fe-O Stretching 635 Fe-O Stretching 510”

  do Nascimento-Dias 等 - 2020 - Detection of organic or inorganic material in Mart DOI: 10.1017/S147355042000021X
• 信頼度 1.0

  “The Raman spectra of the nanocomposites at various Er2O3 concentrations are shown C-Cl bonds induced the strong peaks at 635 and in Figure 4.”

  New Hybrid PVC/PVP Polymer Blend Modified with Er2O3 Nanoparticles for Optoelectronic Applications DOI: 10.3390/polym15030684
• Hydroxyl (O-H) 信頼度 1.0

  “According to FTIR spectra, the stretching bands at 3571 cm-1, vibrations bands at 635 cm-1 originating from OH-groups, as well characteristic bands due to PO ions are clearly visible.”

  Broda 等 - 2019 - Synthesis and selected physicochemical properties DOI: 10.5277/ppmp19073
• Hydroxyl (O-H) 信頼度 1.0

  “The FTIR maxima present at around 635 cm-1 belongs to the that are observed in 3200-3600 spectral region are specific to the H-O-H bands of structural OH groups (stretching and vibrational modes).”

  Development of Silver Doped Hydroxyapatite Thin Films for Biomedical Applications DOI: 10.3390/coatings12030341
• Alkyl C-H 信頼度 1.0

  “cm-1 cm-1 FTIR spectra, typical absorption peaks were observed at 2,956 (C-H), 1720 (C=O), 1,635 cm-1 cm-1 (C=C), 1,250 (C-O-C), and 1,152 (C=O).”

  JI-HYUN 等 - 2019 - Evaluation of physical property and cytotoxicity o DOI: 10.13065/jksdh.20190020
• 信頼度 1.0

  “cm-1 The peak at 634.58 refers to the C-Cl stretching band of the halo compound.”

  James 等 - 2022 - Synthesis and Characterization of Novel Nano-carbo DOI: 10.15376/biores.17.3.4452-4469