What absorbs at 3273 cm⁻¹ in an FTIR spectrum?

Quick answer

A band near 3273 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 3273 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

• confidence 1.0

  “The N-H stretchobserved at 3273cm-1”

  Experimental and theoretical study on the structure and vibrational spectra of β-2-aminopyridinium dihydrogenphosphate DOI: 10.1016/j.saa.2011.03.026
• confidence 1.0

  “Only the spectra of al.9 cm-1 urine (100% and 40%), showed analogous results with the study by Zhang et as the peak at 3273 showed a significant decline in the mean absorbance with time during phase I (Figs.”

  Analysis of the ex-vivo transformation of semen, saliva and urine as they dry out using ATR-FTIR spectroscopy and chemometric approach DOI: 10.1038/s41598-021-91009-5
• confidence 1.0

  “cm-1 2925, 1629, 1320, and 1020 The peak at 3273 that the polyphenols could act as bioreducing agents, while corresponding to N-H stretching of the secondary amide of proteins could play a dual role as bioreducing and stabicm-1 the protein”

  Endophytic fungal isolate mediated biosynthesis of silver nanoparticles and their free radical scavenging activity and anti microbial studies DOI: 10.1007/s13205-016-0433-7
• Hydroxyl (O-H) confidence 1.0

  “cm(cid:0) LOWER) demonstrated quite distinctive differences between 1 The strong peak at 3273 is attributed to stretching vibration of & O-H groups/secondary N-H groups (Al-Amrani, Al-Alawi, Al-Marhobi,”

  Chemical versus infrared spectroscopic measurements of quality attributes of sun or oven dried fruit leathers from apple, plum and apple-plum mixture DOI: 10.1016/j.lwt.2021.112420
• Hydrogen bond confidence 1.0

  “A cm-1 ii) The peak at 3273 can be assigned to the stretch vibration mode containing the intramolecular hydrogen bonds with a major contribution of O6H…O2.”

  Turki 等 - 2018 - Investigation of OH bond energy for chemically tre DOI: 10.1016/j.carbpol.2018.01.030
• Hydroxyl (O-H) confidence 1.0

  “From these findings, the increase in initial encapsulation process, the prepared S/GG-microencapsuand final decomposition temperatures of the S/GG-microlate spectra showed vibrations of several O-H groups at encapsulate over the GG-gum coat”

  Garden cress gum and maltodextrin as microencapsulation coats for entrapment of garden cress phenolic-rich extract: improved thermal stability, storage stability, antioxidant and antibacterial activities DOI: 10.1007/s10068-022-01171-3
• Hydroxyl (O-H) confidence 1.0

  “OH stretching (3273 and -CH2 stretching of alkane (2930 cm-1) and 2855 were the major bond vibrations, originating from the lipid compositions”

  Adnan 等 - 2022 - Microwave-Assisted Synchronous Nanogold Synthesis DOI: 10.3390/ph15020111
• Hydroxyl (O-H) confidence 1.0

  “Assigned OH peaks were 3273 and 3405 regions (nearly 30%) using modulated DSC [31].”

  Al-khattawi 等 - 2014 - Evidence-Based Nanoscopic and Molecular Framework DOI: 10.1371/journal.pone.0101369