What absorbs at 3225 cm⁻¹ in an FTIR spectrum?
A band near 3225 cm⁻¹ can point to several functional groups. Below are the most likely assignments, ranked by how much published evidence supports each — every one traceable to literature (DOI) and cross-validated against our 130,000+ reference spectra and knowledge graph.
Backed by 7 cited sources
Quick answer
A band near 3225 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.
Mogelijke functionele-groeptoewijzingen
| Functionele groep | Ondersteunende feiten | Geciteerde bronnen | Hoogste vertrouwen |
|---|---|---|---|
| Hydroxyl (O-H) | 3 | 3 | 1,0 |
| Alkyl C-H | 2 | 1 | 1,0 |
| N h | 1 | 1 | 1,0 |
| Hydrogen bond | 1 | 1 | 1,0 |
| Methoxy (OCH3) | 1 | 1 | 0,9 |
Ranglijst weerspiegelt cumulatief literatuurbewijs, niet één gezaghebbende regel. Bevestig altijd aan de hand van uw monsterecontext.
Possible materials
| Materiaal | Ondersteunende pieken | Overlapping groups | Geciteerde bronnen |
|---|---|---|---|
| polyaniline | 3225, 1565, 1570 | Alkyl C-H | 1 |
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 3225 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.
Literatuur achter deze toewijzingen
-
Alkyl C-H vertrouwen 1,0
“4(a) show almost the identical bands with N-H vibrational 3 cm-1, rence of 720 nm-PL band indicates the formation of PbI at stage e, and stretching modes at 3225 and 1586 C-H vibrational and”
Hydration of mixed halide perovskites investigated by Fourier transform infrared spectroscopy DOI: 10.1063/1.5087914 -
Hydroxyl (O-H) vertrouwen 1,0
“The broad peak centered at 3225 for the SS the free OH absorption due to the H 2O molecules on represents”
Stopband attenuation of silica spheres by attaching aniline and polyaniline DOI: 10.1016/j.synthmet.2013.03.007 -
Hydroxyl (O-H) vertrouwen 1,0
“cm-1 Around 3225 a negative peak was located, which at the fermentation stage can be associated with the stretching of the O-H bond from the water molecule.”
Mondragon-Cortez 等 - 2022 - Application of Fourier transform infrared spectros DOI: 10.24275/rmiq/Alim2806 -
Hydrogen bond vertrouwen 1,0
“Two broad bands initially located at 3225 and 3495 are correlated with intramolecular hydrogen bonding in CMC sodium salt molecules [17-19].”
Ahmed 等 - 2021 - STRUCTURAL AND OPTICAL CHARACTERISTICS OF POLY(VIN DOI: 10.4314/bcse.v35i3.12 -
Hydroxyl (O-H) vertrouwen 1,0
“At this temperature, the spectrum is dominated by strong water absorpThe isotopic substitution induces frequency shifts of 0, 1, cm-1 cm1, tion bands at 3225, 1628, and 790 assigned to the OH and 5 respectively (Table 2) in the same order o”
Chiral molecule formation in interstellar ice analogs: alpha-aminoethanol NH2CH(CH3)OH DOI: 10.1051/0004-6361/201015342 -
vertrouwen 1,0
“In the case of the APP combinations (L2, L3, L4, L5, L7, L9), the hybrid4+ treated bers showed the characteristic peaks of APP, which are the δN-H and γN-H peaks of NH at 3225 and cm1 cm1, 1430 respectively.”
Prabhakar 等 - 2023 - Hybrid eco-friendly coating on bamboo fabric throu DOI: 10.21203/rs.3.rs-1976669/v1 -
Methoxy (OCH3) vertrouwen 0,9
“From snippet: '3225 OCH3'”
Hadi 等 - 2014 - Formulation and Evaluation of pH-Responsive Mini-T DOI: 10.4314/tjpr.v13i7.3
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