What absorbs at 3449 cm⁻¹ in an FTIR spectrum?

Quick answer

A band near 3449 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.

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 3449 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

• Hydroxyl (O-H) confidence 1.0

  “The spectra have cm-1 cm-1 B Eg energy, is a constant, symbolizes the optical bands at 3449 and 3344 which may be n bandgap energy in electron volts (eV) and can assigned to the stretching vibrations due to the -OH”

  Hydrothermal synthesis of CuO and CeO2/CuO nanostructures: spectroscopic and temperature dependent electrical properties DOI: 10.1007/s10854-021-05423-6
• Hydroxyl (O-H) confidence 1.0

  “cm-1 cm-1 The peaks observed at 3448.83 and 3364.53 assigned to strong O-H stretch (alcohol group).”

  Biosynthesis of TiO2 nanoparticles by Acalypha indica; photocatalytic degradation of methylene blue DOI: 10.1007/s13204-021-01761-3
• Hydroxyl (O-H) confidence 1.0

  “The bands at 3448.72 and 1658.78 are due to O-H stretching and bending vibrations, respectively.”

  Deswardani 等 - 2017 - Study of Structural and Magnetic Properties of Sil DOI: 10.1088/1757-899X/202/1/012047
• Hydroxyl (O-H) confidence 1.0

  “(cm-1) Group Vibration Silica sol Modified silica sol MG resin Silica sol/MG resin O-H Stretching 3449, 1641”

  Qin 等 - 2023 - Preparation and properties of silica solmelamine DOI: 10.1080/15685551.2022.2162280
• Chitosan confidence 1.0

  “FTIR spectra of coconut crab chitosan beads cm-1 FTIR data also shows that the absorption band width in the area of 3448.72 is clearly the OH cm-1 absorption band, but two weak absorption bands between 3748.82-3873.06 in chitosan can be”

  Zam 等 - 2021 - Identification of chitosan beads from coconut crab DOI: 10.1088/1742-6596/1832/1/012014
• confidence 1.0

  “with C ar-O stretching at 1241 The spectra of MC4S 2 (Figure 3B) presents three main bands at cm-1 3449, 1446 and 1051 assigned to the N-H and OH group of both hydroxides for the mesoporous silica and the C4S molecule, the weak absorption p”

  Synthesis and Characterization of Mesoporous Silica Functionalized with Calix[4]arene Derivatives DOI: 10.3390/ijms131013726
• N h confidence 1.0

  “LLM confirmed rule peak-group candidate”

  Fabrication and characterization of a pH-sensitive intelligent film incorporating dragon fruit skin extract DOI: 10.1002/fsn3.2680
• Water (H2O) confidence 1.0

  “LLM confirmed rule peak-group candidate”

  Dorniani 等 - 2016 - Graphene Oxide-Gallic Acid Nanodelivery System for DOI: 10.1186/s11671-016-1712-2