What absorbs at 1346 cm⁻¹ in an FTIR spectrum?
A band near 1346 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 1346 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.
Возможные назначения функциональных групп
| Функциональная группа | Подтверждающие факты | Цитируемые источники | Максимальная достоверность |
|---|---|---|---|
| Alkyl C-H | 4 | 4 | 1,0 |
| Methacrylate | 3 | 3 | 1,0 |
| Acetate | 3 | 3 | 1,0 |
| Methoxy (OCH3) | 2 | 2 | 1,0 |
| C-O single bond | 2 | 2 | 1,0 |
| Fatty acid | 1 | 1 | 1,0 |
| Lipid | 1 | 1 | 1,0 |
| Carbohydrate | 1 | 1 | 1,0 |
| Ketone | 1 | 1 | 1,0 |
| Ester | 1 | 1 | 1,0 |
| Carboxyl (COOH) | 1 | 1 | 1,0 |
| Carbonyl (C=O) | 1 | 1 | 1,0 |
| Amide | 1 | 1 | 1,0 |
| Hydroxyl (O-H) | 1 | 1 | 1,0 |
| N-O bond | 1 | 1 | 1,0 |
| Silicon (Si) | 1 | 1 | 1,0 |
| Nitro (NO2) | 1 | 1 | 0,8 |
Ранжирование отражает накопленные литературные данные, а не единственное авторитетное правило. Всегда проверяйте в контексте вашего образца.
Possible materials
| Материал | Поддерживающие пики | Overlapping groups | Цитируемые источники |
|---|---|---|---|
| pectin | 1346, 1746, 1150 | Methacrylate, Acetate, Alkyl C-H | 1 |
| polyethylene | 1346, 1737, 1720 | Alkyl C-H, Methacrylate, Acetate | 1 |
| polypropylene | 1346, 1030, 1600 | Alkyl C-H, Methacrylate, Acetate | 1 |
| MgO | 1346, 699, 874 | Alkyl C-H, Methoxy (OCH3), Methacrylate | 1 |
| PEG | 1346, 1650, 1342 | Alkyl C-H, Methacrylate, Acetate | 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 1346 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.
Литература, лежащая в основе этих назначений
-
Silicon (Si) достоверность 1,0
“The Raman signature at the 1346.19 cm1 cm1 1491.78 and 1570.94 bonding correspond to D, G-Si and G peaks respectively.”
Swain - 2022 - Process Dependent Strain Behaviour, Fractal Analys DOI: 10.21203/rs.3.rs-374154/v1 -
N-O bond достоверность 1,0
“3ν Figure 2b shows the time-dependent normalized peak areas At the lowest RH of 3.8%, the 3-NO band appears as a cm-1, 3cm-1), ν (833-844 of strong narrow peak at 1346 which is characteristic of 2-NO the signature of the solid phase, cm-1).”
Zhang 等 - 2014 - In Situ Observation on the Dynamic Process of Evap DOI: 10.1021/jp412073c -
достоверность 1,0
“The disappearance of the small peak at cm-1 cm-1 1287 was replaced by the appearance of medium peak at 1346 in the Ag/Cts/PEG spectrum, which was due to the complexation between Cts/PEG and AgNO to form metallopolymer 3 [Ag/Cts/PEG]+.”
Green Synthesis and Characterization of Silver/Chitosan/Polyethylene Glycol Nanocomposites DOI: 10.3390/ijms12084872 -
Alkyl C-H достоверность 1,0
“LLM confirmed rule peak-group candidate”
Synthesis of MgO Nanoparticles Using Artemisia abrotanum Herba Extract and Their Antioxidant and Photocatalytic Properties DOI: 10.1007/s40995-016-0076-x -
Alkyl C-H достоверность 1,0
“The cm-1 The occurrence of the band at 1346 comes probably from bending vibrations of C-H or O-H occurrence of the band at 1346 cm-1 comes probably from bending vibrations of C-H or O-H groups, cm-1 groups, while the presence of distinct ba”
Synthesis and Effect of Structure on Swelling Properties of Hydrogels Based on High Methylated Pectin and Acrylic Polymers DOI: 10.3390/polym11010114 -
Acetate достоверность 1,0
“At 1346 a band related to the cm-1, stretching of the C=O bond of hemicellulose components was displayed.”
Bio-Based Composites for Light Automotive Parts: Statistical Analysis of Mechanical Properties; Effect of Matrix and Alkali Treatment in Sisal Fibers DOI: 10.3390/polym14173566 -
Lipid достоверность 1,0
“Peaks at cm-1 cm-1 1346 and 1446 were attributed to lipids and, in particular, fatty acids and assign”
Complex Spectroscopic Study for Fusarium Genus Fungi Infection Diagnostics of “Zalp” Cultivar Oat DOI: 10.3390/agronomy11122402 -
Alkyl C-H достоверность 1,0
“The the bands at 1517, 1466, 1324 and 1277 which are not present cm-1 band at 1346 is attributed to the bending of the-CH group at oxidation potentials, increase in intensity when the potential 3”
Spectroelectrochemical studies of poly(N-methylaniline) formation, redox behaviour and degradation. A comparison with polyaniline DOI: 10.1016/j.electacta.2013.10.179
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