What absorbs at 3349 cm⁻¹ in an FTIR spectrum?
A band near 3349 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 3349 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.
Penetapan kumpulan berfungsi yang mungkin
| Kumpulan berfungsi | Fakta sokongan | Sumber dipetik | Keyakinan tertinggi |
|---|---|---|---|
| Hydroxyl (O-H) | 6 | 6 | 1.0 |
| N h | 3 | 3 | 1.0 |
| Secondary amine | 2 | 2 | 1.0 |
| Methoxy (OCH3) | 1 | 1 | 1.0 |
| Methacrylate | 1 | 1 | 1.0 |
| Acetate | 1 | 1 | 1.0 |
| C c single bond | 1 | 1 | 1.0 |
| C-O single bond | 1 | 1 | 1.0 |
| Protein | 1 | 1 | 1.0 |
| Hydrogen bond | 1 | 1 | 1.0 |
Pemeringkatan mencerminkan bukti literatur terkumpul, bukan satu peraturan berwibawa. Sentiasa sahkan terhadap konteks sampel anda.
Possible materials
| Bahan | Puncak sokongan | Overlapping groups | Sumber dipetik |
|---|---|---|---|
| TiO2 | 3349, 1700, 1093 | Hydroxyl (O-H), Methoxy (OCH3) | 1 |
| GO | 3349, 1720, 1182 | Hydroxyl (O-H), Methoxy (OCH3) | 1 |
| chitosan | 3349, 1650, 1655 | Hydroxyl (O-H), N h, Methoxy (OCH3) | 1 |
| TiO2 nanoparticles | 3349, 1700, 455 | Hydroxyl (O-H), Methoxy (OCH3), N 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 3349 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.
Literatur di sebalik penetapan ini
-
Hydrogen bond keyakinan 1.0
“The strong peak at 3349 attributed to the intra-molecular hydrogen bonds for (3)O-H-O(5), as shown in Fig.”
Manuscript Preparation Instruction for Publishing in Computer Modeling in Engineering and Science (CMES) DOI: 10.3970/cmc.2018.03608 -
Hydroxyl (O-H) keyakinan 1.0
“After modification, a strong and wide band of O-H that overlapped with N-H band (3349 cm-1) cm-1.”
Synthesis and characterizations of o-nitrochitosan based biopolymer electrolyte for electrochemical devices DOI: 10.1371/journal.pone.0212066 -
Secondary amine keyakinan 1.0
“In peak at 1746 cm-1 cm-1 M4T2,the broad PVP peak FTIR spectrum at 3349 represents the stretching vibration M4T2,the broad PVP peak FTIR spectrum at 3349 cm-1 represents the stretching vibracm-1 of the secondary amine N-H group present in P”
TiO2 Nanoparticle Filler-Based Mixed-Matrix PES/CA Nanofiltration Membranes for Enhanced Desalination DOI: 10.3390/membranes11060433 -
N h keyakinan 1.0
“cm-1 vibration of the sulphonamide (3395 in pure furosemide, 3397 in physical mixtures), NH stretchingvibrationofthesecondaryaminegroup(3348cm-1 3349cm-1 inpurefurosemide, inphysical”
Kovacs 等 - 2020 - Influence of Aqueous Solubility-Enhancing Excipien DOI: 10.3390/pharmaceutics12040385 -
keyakinan 1.0
“3357 and Cd (3353 A decrease in the peak wavenumbers occurred in the spectra for Cu for Cu assigned at a band of 3349 cm-1, Pb (3330 cm-1) and Zn (3341 cm-1).”
Sensitivity and Calibration of the FT-IR Spectroscopy on Concentration of Heavy Metal Ions in River and Borehole Water Sources DOI: 10.3390/app10217785 -
Protein keyakinan 1.0
“The bands between 3349 and 3374 represents the secondary structure of the protein skeleton, which is often used for the quan-”
Tomczynska-Mleko 等 - 2023 - Co-Gelation of Pumpkin-Seed Protein with Egg-White DOI: 10.3390/foods12102030 -
Hydroxyl (O-H) keyakinan 1.0
“LLM confirmed rule peak-group candidate”
Reduced graphene Oxide/NiO based nano-composites for the efficient removal of alizarin dye, indigo dye and reduction of nitro aromatic compounds DOI: 10.1016/j.heliyon.2023.e17162 -
Hydroxyl (O-H) keyakinan 0.9
“Broadest absorption peak around 3349 mainly assigned to O-H stretching.”
Geng 等 - 2020 - Quality Attributes and Microstructure of Cell Wall DOI: 10.3136/fstr.26.281
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