What absorbs at 1231 cm⁻¹ in an FTIR spectrum?
A band near 1231 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
Быстрый ответ
A band near 1231 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 |
|---|---|---|---|
| Amide | 3 | 3 | 1,0 |
| C-O single bond | 2 | 2 | 1,0 |
| Secondary amine | 2 | 2 | 1,0 |
| C c single bond | 2 | 2 | 1,0 |
| Methacrylate | 2 | 2 | 1,0 |
| Acetate | 2 | 2 | 1,0 |
| Phosphorus | 2 | 1 | 1,0 |
| Phosphate (PO4) | 2 | 1 | 1,0 |
| C n single bond | 1 | 1 | 1,0 |
| N h | 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 |
| Methoxy (OCH3) | 1 | 1 | 1,0 |
| Aromatic ring | 1 | 1 | 1,0 |
| Alkyl C-H | 1 | 1 | 1,0 |
Ранжирование отражает накопленные литературные данные, а не единственное авторитетное правило. Всегда проверяйте в контексте вашего образца.
Возможные материалы
| Материал | Поддерживающие пики | Перекрывающиеся группы | Цитируемые источники |
|---|---|---|---|
| protein | 1231, 1650, 1640 | Amide, Secondary amine | 1 |
Материалы отображаются только при поддержке данной полосы и хотя бы одного дополнительного характеристического пика из того же литературного пула.
Логика спектра
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 1231 cm⁻¹ is usually not enough for material identification by itself.
Использование в реальных условиях
Такой тип запроса распространен при идентификации полимеров, скрининге неизвестных пластиков, устранении неполадок в контроле качества, проверке переработанных материалов и анализе отнесения пиков на основе литературы.
Распространенные ошибки
- Рассмотрение одной изолированной полосы как доказательства материала без проверки хотя бы одного или двух поддерживающих пиков.
- Игнорирование перекрытия: несколько функциональных групп могут вносить вклад вблизи одного и того же волнового числа.
- Пропуск проверки, когда добавки, смеси, окисление или загрязнение могут исказить спектр.
Рекомендации по проверке
Когда остается неоднозначность, проверьте гипотезу с помощью DSC, GC-MS или TGA, особенно для смесей, деградированных образцов и наполненных полимеров.
Литература, лежащая в основе этих назначений
-
Alkyl C-H достоверность 1,0
“There is an intermolecular force between the benzene ring of PANI and RGO sheet, therefore, the intensity of ACCEPTED MANUSCRIPT cm-1 cm-1 C-H C-C peaks of the bending of the benzenoid ring at 1231 and the stretching of the benzene ring at”
Highly conductive and flexible silk fabric via electrostatic self assemble between reduced graphene oxide and polyaniline DOI: 10.1016/j.orgel.2017.12.016 -
достоверность 1,0
“1267 O-C-O and Guaiacyl ring Stretching vibration in lignin and xylan 1231 1234 O-C-O and Syringyl ring Stretching vibration in lignin and xylan 1513 1508 Aromatic skeletal vibrations in extractives and lignin 1205”
Jin 等 - 2022 - Rapid Identification for the Pterocarpus Bracelet DOI: 10.3390/molecules27154793 -
Phosphate (PO4) достоверность 1,0
“Similarly, in the cm-1 three groups, an increase in the 1231 band originating from the P=O bond stretching cm-1 vibration in the phosphate groups was observed.”
Synergistic Antifungal Interactions between Antibiotic Amphotericin B and Selected 1,3,4-thiadiazole Derivatives, Determined by Microbiological, Cytochemical, and Molecular Spectroscopic Studies DOI: 10.3390/ijms24043430 -
Acetate достоверность 1,0
“1687cm-1, C=O the positive band at nation bands are originated from stretch of and the positive band at 10cm-1 1246cm-1 1231cm-1.”
Vibrational spectroscopy analysis of ligand efficacy in human M2 muscarinic acetylcholine receptor (M2R) DOI: 10.1038/s42003-021-02836-1 -
Amide достоверность 1,0
“Similar findings were obtained for vibrational modes associated with the cm-1 amide III band from proteins, which illustrates a band peaking at 1231 in unlabeled cm-1 13C14N13C15N-labeled bacteria, 1228 and 1211 in and samples [4].”
Simultaneous Raman and Infrared Spectroscopy of Stable Isotope Labelled Escherichia coli DOI: 10.3390/s22103928 -
C c single bond достоверность 1,0
“1420 corresponded to C-C stretching vibration in the cm-1 at1231cm-1 An absorption band at around 3580 is attributed to benzenering.An absorption band isduetoC-C”
Nabipour 和 Sadr - 2015 - Layered zinc hydroxide-ibuprofen nanohybrids synt DOI: 10.1080/17458080.2014.998301 -
N h достоверность 1,0
“region of 1051 to 1025 C X (where X = Cl, Br, and dance with the literature and proposed structure of quinderivatives.[77-80] All compounds showed two peaks F F) also observed in their respective region, that is, C oline cm-1 stretching vib”
Development of an Efficient, One-Pot, Multicomponent Protocol for Synthesis of 8-Hydroxy-4-Phenyl-1,2-Dihydroquinoline Derivatives DOI: 10.1002/jhet.4193 -
Amide достоверность 1,0
“The presence of BSA within the sample is cm-1, 447 confirmed by the C-N stretch present at 1231 as has previously been seen for other 448 liposomal preparations (Hui & Huang, 2021).”
Weaver 等 - 2022 - Microfluidic-mediated self-assembly of phospholipi DOI: 10.1016/j.ijpharm.2021.121347
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