Hydroxyl (O-H) — FTIR absorption peaks and assignments

Quick answer

Hydroxyl (O-H) is usually assigned by looking for a recurring cluster of characteristic peaks rather than one exact textbook number. The table below shows where the literature most often places this group in FTIR, ranked by accumulated evidence.

Characteristic FTIR peaks for Hydroxyl (O-H)

Showing the 30 best-supported peaks of 1933 total for Hydroxyl (O-H).

Possible materials

Spectrum logic

A functional-group assignment becomes more confident when several expected bands appear together. Use this page to find the strongest-supported peaks, then confirm that the same sample exhibits a coherent pattern rather than a single isolated hit.

Real-world usage

These pages are useful for unknown material analysis, peak explanation in reports, polymer troubleshooting, and verifying whether a candidate material family is chemically plausible.

Common mistakes

• Using one functional-group page as a complete material verdict without checking the rest of the spectrum.
• Assuming the strongest band is always the most diagnostic one.
• Forgetting that processing, additives, aging, and mixtures can shift or broaden expected peaks.

Verification advice

Use DSC, GC-MS, or TGA when several material families share similar bands or when mixture effects make the FTIR assignment uncertain.

Literature behind these assignments

• 3429 cm⁻¹ confidence 1.0

  “LLM confirmed rule peak-group candidate”

  Synthesis and Physical Properties Characterization of Montmorillonite-modified Carbon Nanotubes Filler DOI: 10.1088/1757-899X/546/4/042004
• 731 cm⁻¹ confidence 1.0

  “Unassociated hydroxyl peaks at 731 and 653 in Raman occurred in the compound”

  Quantum chemical studies and vibrational analysis of 4-acetyl benzonitrile, 4-formyl benzonitrile and 4-hydroxy benzonitrile – A comparative study DOI: 10.1016/j.saa.2012.08.053
• 3426 cm⁻¹ confidence 1.0

  “peak in absorption of 3425.6 which showed the 1033.8 While the variation of PA-2 and PA-5 presence of OH bonds.”

  Grafting of Oleic Acid On Cyclic Natural Rubber Resiprene-35 Using Dicumyl Peroxide Initiator and Divinylbenzene Compatibilizers For Paint Binder In Polyamide Thermoplastics DOI: 10.13005/ojc/350119
• 1625 cm⁻¹ confidence 1.0

  “The peak at 1625 in BC was due to OH Quetiapine fumarate at different pH's.”

  pH‐Responsive Studies of Bacterial Cellulose /Chitosan Hydrogels Crosslinked with Genipin: Swelling and Drug Release Behaviour DOI: 10.1002/slct.201902290
• 2925 cm⁻¹ confidence 1.0

  “The and near 2925cm-1 due to vibration of O-H and Cfucoidan standard has eight peaks the same as the H.”

  The Properties of Brown Marine Algae Sargassum turbinarioides and Sargassum ilicifolium Collected From Yogyakarta, Indonesia DOI: 10.14499/indonesianjpharm30iss1pp43
• 3409 cm⁻¹ confidence 1.0

  “The FTIR bands observed at 3409 and 1621 are due to the O-H stretching mode of hydroxyl group.”

  Synthesis and Characterization of Spindle-Like TiO2 Nanostructures and Photocatalytic Activity on Methyl Orange and Methyl Blue Dyes Under Sunlight Radiation DOI: 10.1007/s10876-017-1245-6
• 842 cm⁻¹ confidence 1.0

  “6observed in the wavenumber region 820-870 The investigation of peak profile of PF a band with octahedral symmetry (O h) of polymer salt system (Fig 8 a) suggests the presence of asymmetry in the characteristic band with cm-1 maxima at 842”

  Arya 等 - 2018 - Effect of variation of different nanofillers on st DOI: 10.1007/s11581-016-1784
• 1628 cm⁻¹ confidence 1.0

  “Fourier-Transform Infrared (FTIR) Spectroscopy cm-1, prominent peaks appeared at 1627.5 and 3350 representing N-H bond and hydroxyl The chemical and structural characteristics of nanocomposites, as well as their atomic bond stretching vibra”

  Electro-Oxidation of Metal Oxide-Fabricated Graphitic Carbon Nitride for Hydrogen Production via Water Splitting DOI: 10.3390/coatings12050548