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
Hiter odgovor
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.
Možne dodelitve funkcionalnih skupin
| Funkcionalna skupina | Podporna dejstva | Citirani viri | Najvišje zaupanje |
|---|---|---|---|
| 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 |
Razvrstitev odraža zbrane literaturne dokaze, ne enega avtoritativnega pravila. Vedno preverite glede na kontekst vašega vzorca.
Logika spektra
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.
Uporaba v resničnem svetu
Ta vrsta poizvedbe je pogosta pri identifikaciji polimerov, pregledovanju neznanih plastičnih mas, odpravljanju težav pri QC, preverjanju recikliranih materialov in literaturno podprtem pregledu dodelitev vrhov.
Pogoste napake
- Obravnavanje enega izoliranega pasu kot dokaza o materialu brez preverjanja vsaj enega ali dveh podpornih vrhov.
- Ignoriranje prekrivanja: več funkcionalnih skupin lahko prispeva blizu istega valovnega števila.
- Izpuščanje validacije, ko lahko dodatki, mešanice, oksidacija ali kontaminacija popačijo spekter.
Nasvet za preverjanje
Ko ostaja dvoumnost, potrdite hipotezo z DSC, GC-MS ali TGA, zlasti za mešanice, degradirane vzorce in polnjene polimere.
Literatura za temi dodelitvami
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Silicon (Si) zaupanje 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) zaupanje 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) zaupanje 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 -
zaupanje 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) zaupanje 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) zaupanje 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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