What absorbs at 1779 cm⁻¹ in an FTIR spectrum?
A band near 1779 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 5 cited sources
Hiter odgovor
A band near 1779 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 |
|---|---|---|---|
| Carbonyl (C=O) | 5 | 5 | 1,0 |
| Imide | 2 | 2 | 1,0 |
| Ring structure | 1 | 1 | 1,0 |
| Alkyl C-H | 1 | 1 | 1,0 |
Razvrstitev odraža zbrane literaturne dokaze, ne enega avtoritativnega pravila. Vedno preverite glede na kontekst vašega vzorca.
Možni materiali
| Material | Podporni vrhovi | Prekrivajoče se skupine | Citirani viri |
|---|---|---|---|
| polyimide | 1779, 1720, 1778 | Carbonyl (C=O), Imide | 1 |
Materiali so prikazani le, ko ista literaturna podlaga podpira ta pas in vsaj en dodatni karakteristični vrh.
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 1779 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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Imide zaupanje 1,0
“the unaged CBR 320/328 composites reveal three imide carbonyl peaks at 1779, 1728 and 1712 These peaks may be assigned to the symmetric and asymmetric stretches of an unsaturated imide (1779 and 1728 cm(cid:2)1)”
Fox 等 - 2004 - Investigation of failure mechanisms in aged aerosp DOI: 10.1016/j.engfailanal.2003.05.010 -
Carbonyl (C=O) zaupanje 1,0
“Fourier Transt Copyright: American Scientific Publishers cm-1, form Infrared Spectroscopy (FTIR) spectra shows two new absorbance peaks at 1779 and 1851 which i Delivered by Ingenta c correspond to symmetrical and asymmetrical stretching vi”
Compatibilization effect of EVA-g-MAH on mechanical, morphological and rheological properties of recycled PC/ABS blend DOI: 10.1166/mex.2014.1198 -
Alkyl C-H zaupanje 1,0
“Peaks that can only be assigned to polyimide in the blend include the methyl group C-H stretching cm-1), cm-1), C=O (symmetric stretching) (1779 C=O (anti-symetric stretching) (2957-2863 cm-1),”
Maab 等 - 2009 - SPEEKPolyimide Blends for Proton Conductive Membr DOI: 10.1002/fuce.200800121 -
Carbonyl (C=O) zaupanje 1,0
“In the FTIR cm(cid:3)1 spectrum strong absorption bands appeared at 1779 due to the asymmetric vibration of the carbonyl imide ring, at 1719 cm(cid:3)1 attributed to the symmetric vibration of carbonyl imide”
Serbezeanu 等 - 2016 - Phosphorus-containing polyimide fibers and their t DOI: 10.1039/c6ra06497c -
Carbonyl (C=O) zaupanje 0,95
“Explicit assignment: 'the C=O (of SMA) peak at a wavelength of 1779'”
The effect of Styrene Maleic Anhydride on the microstructure evolution of PSF-based membrane prepared by thermal-induced phase separation method DOI: 10.1016/j.mtcomm.2019.100687
Imate spekter s tem pasom?
Naložite svoj FTIR spekter in v nekaj sekundah pridobite celotno poročilo o interpretaciji — dodelitve vrhov z literaturnimi citati, ujemanja knjižnice in verigo dokazov z oceno zaupanja.