What absorbs at 1363 cm⁻¹ in an FTIR spectrum?
A band near 1363 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 1363 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
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| Alkyl C-H | 7 | 7 | 1.0 |
| Methoxy (OCH3) | 2 | 2 | 1.0 |
| Methacrylate | 2 | 2 | 1.0 |
| Amide | 2 | 2 | 1.0 |
| Acetate | 2 | 2 | 1.0 |
| N-O bond | 2 | 2 | 1.0 |
| Alkene (C=C) | 2 | 2 | 1.0 |
| Hydroxyl (O-H) | 2 | 2 | 1.0 |
| Carboxyl (COOH) | 2 | 1 | 1.0 |
| Ketone | 1 | 1 | 1.0 |
| Ester | 1 | 1 | 1.0 |
| Carbonyl (C=O) | 1 | 1 | 1.0 |
| Nitro (NO2) | 1 | 1 | 1.0 |
| C-O single bond | 1 | 1 | 1.0 |
| Carbohydrate | 1 | 1 | 0.7 |
| Protein | 1 | 1 | 0.7 |
| Silicon-oxygen (Si-O) | 1 | 0 | 1.0 |
Ranking reflects accumulated literature evidence, not a single fixed rule. Always confirm against your sample context.
Possible materials
| Material | Supporting peaks | Overlapping groups | Cited sources |
|---|---|---|---|
| chitosan | 1363, 1650, 1655 | Alkyl C-H, Amide, Methacrylate | 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 1363 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
-
Alkyl C-H confidence 1.0
“The peaks observed at 1363 and 3 2 cm-1 1466 represent C-H deformation vibration bands [33,34].”
n-Heptadecane-Impregnated Wood as a Potential Material for Energy-Saving Buildings DOI: 10.3390/f13122137 -
Alkyl C-H confidence 1.0
“cm-1 (CH symmetric stretch), 1666 (C=O stretching vibration), 1438 (C-N stretching vibration), 3 cm-1 cm-1 cm-1 1363 (CH bending vibration), 1155 (C-O-C bending vibration), and 1073 (C-OH 3”
Synthesis, Characterization, and Antibacterial Activity of Cross-Linked Chitosan-Glutaraldehyde DOI: 10.3390/md11051534 -
N-O bond confidence 1.0
“3 (cid:2) (cid:3)72%, (cid:2) 33cm-1 3-NO band at 1363 and 1390 at the RH of instead of the single 3-NO band of the cm-1 at 1357 for the initial solid NaNO 3, was observed.”
Lu 等 - 2008 - Molecular events in deliquescence and efflorescenc DOI: 10.1063/1.2973623(cid:5) -
Amide confidence 1.0
“The 1439cm(cid:1)1 References in shifting of amide bands from 1363,”
Saba 等 - 2019 - Potential role of bacterial extracellular polymeri DOI: 10.1080/10889868.2019.1602107 -
Hydroxyl (O-H) confidence 1.0
“Also, 188 cm-1 the peak at 1363 of BG melanin was attributed to OH deformation and C-O stretching of 189 D”
Isolation and characterization of melanin from black garlic and sepia ink DOI: 10.1016/j.lwt.2018.09.033 -
Hydroxyl (O-H) confidence 1.0
“spectra gave peaks at 1080.12 (C-O-C stretch), 2910 (for O-H cm-1 (carbonyl peak), 1027 cm-1 (for C-O-C stretch), as well as 763 cm-1 (for C-Cl 1672 cm-1 stretching), 2910 (CH, stretch), and 1362.68 cm-1 (for OH bending vibrations).”
Awais 等 - 2023 - Enhanced Solubility and Stability of Aripiprazole DOI: 10.3390/molecules28093860 -
Alkyl C-H confidence 1.0
“The band at 1456cm-1 1363cm-1 ria, Gram-negative Pseudomonas aeruginosa (5994 NLF), indicates CH bending.”
Dar 等 - 2022 - Efficacy of Various Types of Berries Extract for t DOI: 10.1155/2023/9815767 -
confidence 1.0
“peaks around 1424 and 1363cm-1 with in situ generated trimetallic (Bi, Fe, and Sn) corresponds to CH deformation modes and the 2 Journal of Chemistry 5 100 80 Transmittance 60 40 20 3500 3000 2500 2000 1500 1000 Wavenumber (cm-1) (a) 100 80”
Dar 等 - 2023 - Study of Antimicrobial Potency of Synthesized Cell DOI: 10.1155/2023/6122583
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