What absorbs at 1408 cm⁻¹ in an FTIR spectrum?
A band near 1408 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 1408 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.
可能性のある官能基アサイン
| 官能基 | 裏付け事実 | 引用元 | 最高信頼度 |
|---|---|---|---|
| Alkyl C-H | 11 | 10 | 1.0 |
| Amide | 9 | 9 | 1.0 |
| Acetate | 8 | 8 | 1.0 |
| Methacrylate | 7 | 7 | 1.0 |
| Carbonyl (C=O) | 6 | 6 | 1.0 |
| Methoxy (OCH3) | 5 | 5 | 1.0 |
| N h | 5 | 5 | 1.0 |
| Carboxyl (COOH) | 5 | 4 | 1.0 |
| Secondary amine | 4 | 4 | 1.0 |
| C-O single bond | 4 | 4 | 1.0 |
| Aromatic ring | 4 | 3 | 1.0 |
| C n single bond | 3 | 3 | 1.0 |
| Amino acid | 3 | 3 | 1.0 |
| Ketone | 3 | 3 | 1.0 |
| Ester | 3 | 3 | 1.0 |
| Methyl | 2 | 2 | 1.0 |
| Ring structure | 2 | 2 | 1.0 |
| Lipid | 2 | 2 | 1.0 |
| C c single bond | 2 | 2 | 1.0 |
| S eq o | 1 | 1 | 1.0 |
| Sulfonyl | 1 | 1 | 1.0 |
| Alkene (C=C) | 1 | 1 | 1.0 |
| Acetyl | 1 | 1 | 1.0 |
| Carbohydrate | 1 | 1 | 1.0 |
| Protein | 1 | 1 | 1.0 |
| Carbonate | 1 | 1 | 1.0 |
| Protein beta sheet | 1 | 1 | 1.0 |
| Hydroxyl (O-H) | 1 | 1 | 1.0 |
| Fluorine (C-F) | 1 | 1 | 0.9 |
| Boron nitrogen | 1 | 0 | 1.0 |
ランキングは蓄積された文献証拠を反映しており、単一の権威あるルールではありません。常にサンプルのコンテキストと照合して確認してください。
Possible materials
| 素材 | 補助ピーク | Overlapping groups | 引用元 |
|---|---|---|---|
| PET | 1408, 800, 1205 | Methacrylate, Acetate, Alkyl C-H | 1 |
| TiO2 | 1408, 1700, 1093 | Alkyl C-H, Methacrylate, Acetate | 1 |
| Al2O3 | 1408, 1722, 1383 | Methacrylate, Acetate, 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 1408 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.
これらのアサインの根拠となる文献
-
Alkyl C-H 信頼度 1.0
“Among the more intense bands, we observe in the IR SE spectra the characteristic bands corresponding to the vibration modes of the trans C-O stretch (~976 cm-1), the ester C-C, C-O stretch (~1024 cm-1), the ethylene glycol CH2 wagging mode”
Laskarakis 等 - 2004 - A Spectroscopic Ellipsometry study of PET membrane DOI: 10.1002/masy.200450109 -
Amide 信頼度 1.0
“The maximum of 73.1% of antiindicates asymmetric O-H stretching, 1637.7 oxidation activity was indicated by EPsC at 1000 µg/mL but cm-1 represents the Amide I band, and 1408.08 represents”
Lavania 等 - 2023 - Anatomizing extracellular polymer of Calothrix des DOI: 10.14719/pst.2615 -
Carbonyl (C=O) 信頼度 1.0
“The peak at 1408 is due to the cm-1 symmetric stretching of carbonyl group.”
Structural, optical, morphological and thermal properties of TiO2–Al and TiO2–Al2O3 composite powders by ball milling DOI: 10.1016/j.physleta.2017.02.053 -
Acetate 信頼度 1.0
“Compared with P, the spectra of the EP showed the appearance of cm-1, cm-1,1408 cm-1, 1598 which were represented C=O stretching vibration, strong bands at 1743 C=O asymmetric stretching vibration and O-H deformation vibration respectively.”
Ouyang 等 - 2012 - Adsorption of Cu (II) from aqueous single metal so DOI: 10.4028/www.scientific.net/AMR.535-537.1601 -
信頼度 1.0
“According to the spectra illustrated in Fig.3, besides the CO interference band 2 cm-1, cm-1, near 2350 the bands near 1408 and 871 which correspond to amino acids and 1,2,4-three substituted benzene,”
Xia 等 - 2015 - Removal of Natural Organic Matter by Forward Osmos DOI: 10.1007/s40242-015-4374-1 -
Carbonyl (C=O) 信頼度 1.0
“The FTIR spectrum of the blend membrane showed new peaks at 1669 cm-1 and 1408 cm-1, corresponding to the carbonyl C=O stretching vibration and the O-H bending vibration of the carboxyl group, respec-”
Preparation and Characterization of Polymer Membranes Impregnated with Carbon Nanotubes for Olive Mill Wastewater DOI: 10.3390/polym14030457 -
Amide 信頼度 1.0
“The carbonyl absorption band at 1735 cm-1 27, suggested the presence of an acrylic-based emulsion whereas the presence of the amide stretching at 1408”
Chemically stable Au nanorods as probes for sensitive surface enhanced scattering (SERS) analysis of blue BIC ballpoint pens DOI: 10.1063/1.4997132 -
Amino acid 信頼度 1.0
“COOperenne are slightly higher (65 and 71%, Table 4) compared at 1236 amino acids, as illustrated by the cm-1, to the classification results of approach 1 (46 and 64%, stretching mode at 1408 and carbohydrates, the latter Table 2).”
Discrimination of grass pollen of different species by FTIR spectroscopy of individual pollen grains DOI: 10.1007/s00216-020-02628-2
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