What absorbs at 2991 cm⁻¹ in an FTIR spectrum?
A band near 2991 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
クイックアンサー
A band near 2991 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
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。
可能性のある材料
| 素材 | 補助ピーク | 重複グループ | 引用元 |
|---|---|---|---|
| TiO | 2991, 1730, 1699 | Alkyl C-H | 1 |
| rGO | 2991, 2358, 2930 | Alkyl C-H | 1 |
| PLA | 2991, 1650, 1073 | Alkyl C-H | 1 |
| PEG | 2991, 1650, 1342 | Alkyl C-H | 1 |
| PLLA | 2991, 1182, 921 | Alkyl C-H, Methyl | 1 |
同じ文献プールがこのバンドと少なくとも1つの追加の特性ピークをサポートする場合にのみ、材料が表示されます。
スペクトルロジック
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 2991 cm⁻¹ is usually not enough for material identification by itself.
実使用例
この種のクエリは、ポリマー識別、未知のプラスチックスクリーニング、QCトラブルシューティング、リサイクル材料の検証、および文献に基づいたピーク帰属のレビューで一般的です。
よくある間違い
- 少なくとも1～2つの支持ピークを確認せずに、1つの孤立したバンドを材料の証拠として扱うこと。
- 重複を無視: 複数の官能基が同じ波数付近に寄与することがあります。
- 添加剤、ブレンド、酸化、または汚染がスペクトルを歪める可能性がある場合に検証を省略すること。
検証アドバイス
曖昧さが残る場合は、特にブレンド、劣化サンプル、充填ポリマーについて、DSC、GC-MS、またはTGAで仮説を検証してください。
これらのアサインの根拠となる文献
-
Alkyl C-H 信頼度 1.0
“The two cm-1 bands at 2991 and 2948 can be attributed to the C-H bond stretching vibrations of the -CH and”
Awad 等 - 2020 - Experimental Investigation of Methyl Methacrylate DOI: 10.3390/ma13245793 -
Alkyl C-H 信頼度 1.0
“LLM confirmed rule peak-group candidate”
Structural and Surface Compatibility Study of Modified Electrospun Poly(ε-caprolactone) (PCL) Composites for Skin Tissue Engineering DOI: 10.1208/s12249-016-0500-8 -
Alkyl C-H 信頼度 1.0
“The characteristic band at 2991 cm-1 to 2976 cm-1 cm-1 cm-1 (C=C 2976 corresponds to C-H stretching vibrations, 1652 skeletal vibration), 1521”
Complex Permittivity and Electromagnetic Interference Shielding Effectiveness of OPEFB Fiber-Polylactic Acid Filled with Reduced Graphene Oxide DOI: 10.3390/ma13204602 -
Alkyl C-H 信頼度 1.0
“The asymmetric and symmetric C-H stretching (St.) cm1 cm1, of the methyl groups were attributed to the transmission bands at 2991 and 2943 respectively.”
Ragab - 2022 - Improved Physical, thermal, and conductivity stren DOI: 10.21203/rs.3.rs-1514992/v1 -
Alkyl C-H 信頼度 1.0
“The bands at 2991 and 2868 which were attributed to various C-H stretching vibrations, had opposite signs on the PC2 and PC3 loading curves.”
Ex Vivo Vibration Spectroscopic Analysis of Colorectal Polyps for the Early Diagnosis of Colorectal Carcinoma DOI: 10.3390/diagnostics11112048 -
Methyl 信頼度 0.9
“Explicit assignment: CH3 asymmetric stretching”
Differentiation in MALDI-TOF MS and FTIR spectra between two pathovars of Xanthomonas oryzae DOI: 10.1016/j.saa.2014.06.056 -
Methyl 信頼度 0.9
“Explicit assignment: 'absorption peak around 2991 ... stretching vibration peak of CH3'”
Li 等 - 2020 - Effect of molecular weight of polyethylene glycol DOI: 10.1039/d0ra08699a -
Alkyl C-H 信頼度 0.8
“Text: 'strong peak at 2991.3 cm-1 (Q is assigned as the center branch) ... R(2) transition of our 5ν C-H'”
Perez-Delgado 和 Manzanares - 2010 - Cavity Ring Down and Fourier Transform Infrared Sp DOI: 10.1021/jp105382p
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