What absorbs at 904 cm⁻¹ in an FTIR spectrum?
A band near 904 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 7 cited sources
Quick answer
A band near 904 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 |
|---|---|---|---|
| Methacrylate | 2 | 2 | 1,0 |
| Acetate | 2 | 2 | 1,0 |
| Oxygen heterocycle | 2 | 2 | 1,0 |
| Silicon nitrogen | 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 |
| Methoxy (OCH3) | 1 | 1 | 1,0 |
| C-O single bond | 1 | 1 | 1,0 |
| Ring structure | 1 | 1 | 1,0 |
| Silicon (Si) | 1 | 1 | 1,0 |
| Alkyl C-H | 1 | 1 | 1,0 |
| Hydroxyl (O-H) | 1 | 0 | 1,0 |
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 |
|---|---|---|---|
| bio-based | 904, 1720, 1740 | 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 904 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
-
Alkyl C-H достоверность 1,0
“The peak at 904 corresponds to the C - H bond deformation or to the C - N cm-1 C bond of the protein backbone.”
Depciuch 和 Parlinska-Wojtan - 2018 - Comparing dried and liquid blood serum samples of DOI: 10.1016/j.jpba.2017.11.074 -
Silicon (Si) достоверность 1,0
“2 X x film indicates that the N atoms were incorporated in the a-Si due to 766-884cm-1 904cm-1 nitridation.”
Growth of silicon nitride by nitridation of amorphous silicon at low temperature in hot-wire CVD DOI: 10.1016/j.mssp.2017.05.015 -
Oxygen heterocycle достоверность 1,0
“In addition, after modification, FTIR peaks that assigned to the epoxy ring (844 cm-1 and 904 cm-1) were decreased.”
Mazlan 和 Abu Hanifah - 2014 - Synthesis and Effect of Modification On Methacylat DOI: 10.1063/1.4895206 -
Oxygen heterocycle достоверность 1,0
“Explicit assignment in text.”
New reactive isoeugenol based phosphate flame retardant: toward green epoxy resins DOI: 10.1021/acssuschemeng.9b02629 -
Acetate достоверность 1,0
“1636 cm-1, assigned to C-O stretching vibration and on the preparation route of the C-CPS/W hybrids, one about 904 cm-1, which could be assigned to the conformation change in the secondary structure et al.”
Radev 等 - 2009 - OrganicInorganic bioactive materials Part II in DOI: 10.2478/s11532-009-0076-1 -
Acetate достоверность 1,0
“The satellite band at 904 cm-1 is due to the C=O*”
Plasticizers and Salt Concentrations Effects on Polymer Gel Electrolytes Based on Poly (Methyl Methacrylate) for Electrochemical Applications DOI: 10.3390/gels8060363 -
Silicon nitrogen достоверность 1,0
“The broad absorption bands due to Si-O (1026 Si-N (904 cm-1)”
Porous Silicon Oxycarbonitride Ceramics with Palladium and Pd2Si Nanoparticles for Dry Reforming of Methane DOI: 10.3390/polym14173470
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