What absorbs at 787 cm⁻¹ in an FTIR spectrum?
A band near 787 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 6 cited sources
Quick answer
A band near 787 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 |
|---|---|---|---|
| Silicon-oxygen (Si-O) | 5 | 5 | 1.0 |
| Silicon (Si) | 3 | 3 | 1.0 |
| Siloxane (Si-O-Si) | 2 | 2 | 1.0 |
| Silicon silicon | 1 | 1 | 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。
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 787 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
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Silicon (Si) 信頼度 1.0
“The Infrared (IR) spectra showed peaks at 461.231 787.381 cm-1, Si∼O∼Si Si∼O∼Si and 1045.99 which corresponds to the bending vibration, the Si∼O∼Si stretch vibration, and the stretching vibration, respectively.”
Green Synthesis of Crystalline Silica from Sugarcane Bagasse Ash: Physico-Chemical Properties DOI: 10.3390/nano12132184 -
Silicon (Si) 信頼度 1.0
“The band at wavenumber 907 cm-1 corresponds to the O-H deformation of the internal hydroxyl groups, and that at 787 cm-1 is due to a symmetrical Si-O stretching vibra-”
Morphology and Selected Properties of Modified Potato Thermoplastic Starch DOI: 10.3390/polym15071762 -
Silicon-oxygen (Si-O) 信頼度 1.0
“However, the band shown at wavenumber 787 indicates bending in quartz (Toor 2015).”
Musie 和 Gonfa - 2023 - Thermal activation, characterization and performan DOI: 10.2166/wst.2023.031 -
信頼度 1.0
“700.7463 Si-O stretching, Si-O-Al stretching 786.5672 Si-O stretching, Si-O-Al stretching, (Al, Mg)-O-H, Si-O-(Mg, Al) stretching 908.2090 Al 2OH, AL-O-H vibrations”
Structural Study of Nano-Clay and Its Effectiveness in Radiation Protection against X-rays DOI: 10.3390/nano12142332 -
Silicon (Si) 信頼度 1.0
“FTIR analysis showed peaks in the spectral region of 520, 675, 787, 917, 1030 and 1093 cm-1 which are bending vibrations of symmetric and asymmetric TOT (tetrahedral layers of silicon coordinated with oxygen) (T = Al, Mg, Si and Fe) opening”
Bentonites Modified with Phosphomolybdic Heteropolyacid (HPMo) for Biowaste to Biofuel Production DOI: 10.3390/ma12091431 -
Siloxane (Si-O-Si) 信頼度 0.9
“Explicit assignment in text.”
Mazumder 等 - 2014 - Structural and optical characterization of fresh w DOI: 10.1117/12.2039793
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