What absorbs at 776 cm⁻¹ in an FTIR spectrum?
A band near 776 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 776 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 |
|---|---|---|---|
| Silicon-oxygen (Si-O) | 5 | 5 | 1,0 |
| Silicon (Si) | 3 | 3 | 1,0 |
| Metal oxygen | 1 | 1 | 1,0 |
| Siloxane (Si-O-Si) | 1 | 1 | 1,0 |
| Carboxyl (COOH) | 1 | 1 | 1,0 |
| Secondary amine | 1 | 1 | 1,0 |
| N h | 1 | 1 | 1,0 |
| Ester | 1 | 1 | 1,0 |
| Methyl | 1 | 1 | 1,0 |
| Alkyl C-H | 1 | 1 | 1,0 |
| Phosphate (PO4) | 1 | 1 | 1,0 |
| Aromatic ring | 1 | 1 | 0,8 |
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 |
|---|---|---|---|
| NiO | 776, 1006, 1450 | Metal oxygen | 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 776 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
-
Phosphate (PO4) достоверность 1,0
“The cm-1, assignments of the phosphate related peaks are as follows: P-O stretching at 776 P-O-C cm-1,”
An appraisal of the thermal decomposition mechanisms of ILs as potential lubricants DOI: 10.1002/ls.1457 -
Alkyl C-H достоверность 1,0
“in vitro duced during incubation is based on methyl ester of cm-1, Produced CLA showed a weak peak at 776 which fatty acid by GC analysis (Devillard et al.”
Optimization of food-grade medium for co-production of bioactive substances by Lactobacillus acidophilus LA-5 for explaining pharmabiotic mechanisms of probiotic DOI: 10.1007/s13197-020-04894-5 -
N h достоверность 1,0
“Moreover, it is worth mentioning that F8815 has only primary amino groups as proved by the pair of peaks at 806 and 776 cm-1 cm-1 (NH bending, inset) [36], and the relative strong band at 1639 (NH stretching).”
Bellido-Aguilar 等 - 2019 - Effect of a fluoroalkyl-functional curing agent on DOI: 10.1016/j.surfcoat.2019.02.006 -
Carboxyl (COOH) достоверность 1,0
“The band cm-1 cm-1 at 776 was characterized as typical for guluronic acid [33] as well as the 791 cm-1 C.”
Soluble Extracellular Polymeric Substances Produced by Parachlorella kessleri and Chlorella vulgaris: Biochemical Characterization and Assessment of Their Cadmiumand Lead Sorption Abilities DOI: 10.3390/molecules27217153 -
достоверность 1,0
“was observed with a peak at 1270 cm-1, and the absorption bands related to the stretching vibrations of the Si-C bond and/or the stretching vibrations of the Si-O bond were observed at 776 cm-1 [35].”
Organic Bio-Based Aerogel from Food Waste: Preparation and Hydrophobization DOI: 10.3390/gels8110691 -
Silicon (Si) достоверность 1,0
“cm(cid:4)1 range [39, 40], whereas the band at 776 was the initial substitution of NiO/ CaO, the absorption related to the Si-O-Si symmetric stretches of nonedge exhibited gradual red shift (shift longer wavebridging oxygen atoms between te”
Impact of high NiO content on the structural, optical, and dielectric properties of calcium lithium silicate glasses DOI: 10.1007/s10854-022-08045-8 -
достоверность 1,0
“A new peak at 776 assigned to the Mn-O bond was found in cm-1 MnDBC, F 1M 3DBC, and F 3M 1DBC, while a new peak at 558 belonging to the Fe-O bond was found in FDBC, F 1M 3DBC, and F 3M 1DBC, which illustrated the formation of Fe oxides, Mn”
Liang 等 - 2022 - Adsorption of Atrazine by Fe-Mn-Modified Biochar DOI: 10.3390/agronomy12123097 -
Silicon (Si) достоверность 1,0
“Aromatic ring substitution is seen at 879 and 776 cm-1 Si-O 1425 region includes C stretching of heteroaromatic [57, 58].”
Biochar from co-pyrolysis of urban organic wastes—investigation of carbon sink potential using ATR-FTIR and TGA DOI: 10.1007/s13399-020-01000-9
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