What absorbs at 3293 cm⁻¹ in an FTIR spectrum?
A band near 3293 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 8 cited sources
Quick answer
A band near 3293 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.
Possibili assegnazioni di gruppi funzionali
| Gruppo funzionale | Fatti di supporto | Fonti citate | Affidabilità massima |
|---|---|---|---|
| N h | 5 | 5 | 1,0 |
| Alkyl C-H | 5 | 5 | 1,0 |
| Hydroxyl (O-H) | 5 | 5 | 1,0 |
| Amide | 2 | 2 | 1,0 |
| Methoxy (OCH3) | 1 | 1 | 1,0 |
| Methacrylate | 1 | 1 | 1,0 |
| C-O single bond | 1 | 1 | 1,0 |
| Acetate | 1 | 1 | 1,0 |
| Carboxyl (COOH) | 1 | 1 | 1,0 |
| Phenolic | 1 | 1 | 0,8 |
La classifica riflette le prove bibliografiche accumulate, non una singola regola autorevole. Conferma sempre nel contesto del tuo campione.
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 3293 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.
Letteratura dietro queste assegnazioni
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Alkyl C-H affidabilità 1,0
“cm-1) The acetylenic C≡C bond stretching (2110 and acetylenic ≡C-H bond stretching (3293 peaks of 2-ethynylpyridine monomer were not seen in the FT-IR spectrum of polymer.”
Gal 等 - 2016 - Synthesis and Characterization of a Water-Soluble DOI: 10.12693/APhysPolA.129.642 -
Hydroxyl (O-H) affidabilità 1,0
“As observed, 𝜈, cm-1 a dominant broad peak centered at 3293 is due to the hydroxyl stretching vibrations.”
Power-Dependent Nonlinear Optical Behaviours of Ponceau BS Chromophore at 532 nm via Z-Scan Technique DOI: 10.1016/j.jphotochem.2020.112574 -
Alkyl C-H affidabilità 1,0
“- - - - O-H asymmetric and symmetric stretching 3293 3356 C-H asymmetric and symmetric stretching 2876 2872 2881 2858 2851 2851 vibration - - - - C=O stretching in aldehydes 1772 1778 - - - - - N-H bending of NH group (scissoring) 1673 2 -”
Sukprasert 等 - 2020 - Synchrotron FTIR Light Reveals Signal Changes of B DOI: 10.1155/2020/6149713 -
affidabilità 1,0
“sin2 1.83 N-H bend 1184 131 N-H(cid:5)(cid:5)(cid:5) stretching 3293 249 N-H stretching 3345”
Ay 和 Aydinli - 2004 - Comparative investigation of hydrogen bonding in s DOI: 10.1016/j.optmat.2003.12.004 -
Hydroxyl (O-H) affidabilità 1,0
“In the spectrum of pure capsaicin, the broad cm-1 cm-1 absorption peaks at 3293.43 and 2926.43 might be associated with the stretching of -OH bond and -C-H aliphatic stretching vibrations, respectively;”
Microencapsulation of Capsaicin in Chitosan Microcapsules: Characterization, Release Behavior, and Pesticidal Properties against Tribolium castaneum (Herbst) DOI: 10.3390/insects14010027 -
affidabilità 1,0
“Peaks observed at 3293 cm-1 cm-1 3293 and 3363 are indicative of the presence of the stretching vibrations of the amine group cm-1 and 3363 cm-1 are indicative of the presence of the stretching vibrations of the amine group in the”
Effect of the Zwitterion, p(MAO-DMPA), on the Internal Structure, Fouling Characteristics, and Dye Rejection Mechanism of PVDF Membranes DOI: 10.3390/membranes10110323 -
affidabilità 1,0
“A strong peak at 3293 was designated as the N-H stretching vibration of the peptide groups and termed amide A.”
Extracellular vesicles derived from microgreens of Raphanus sativus L. var. caudatus Alef contain bioactive macromolecules and inhibit HCT116 cells proliferation DOI: 10.1038/s41598-022-19950-7 -
Hydroxyl (O-H) affidabilità 1,0
“Effect of virus titer on characteristic spectra peak height The most significant differences were found for the at 8 h.p.i cm-1, peak at 3293 The characteristic peaks of the BGMK cell line showed assigned to OH stretching (One-way 106 chang”
Lee-Montiel 等 - 2011 - Detection and quantification of poliovirus infecti DOI: 10.1186/1754-1611-5-16
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