What absorbs at 849 cm⁻¹ in an FTIR spectrum?
A band near 849 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
Hiter odgovor
A band near 849 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 |
|---|---|---|---|
| Methoxy (OCH3) | 3 | 3 | 1,0 |
| Methacrylate | 3 | 3 | 1,0 |
| C-O single bond | 3 | 3 | 1,0 |
| Acetate | 3 | 3 | 1,0 |
| Alkyl C-H | 3 | 3 | 1,0 |
| Hydroxyl (O-H) | 2 | 2 | 1,0 |
| Silicon-oxygen (Si-O) | 2 | 2 | 1,0 |
| Silicon nitrogen | 1 | 1 | 1,0 |
| Silicon (Si) | 1 | 1 | 1,0 |
| Carbohydrate | 1 | 1 | 0,8 |
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 |
|---|---|---|---|
| PVA | 849, 1660, 2930 | Acetate, Methacrylate, C-O single bond | 1 |
| Polypyrrole | 849, 1700, 400 | Methacrylate, Acetate | 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 849 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
-
Hydroxyl (O-H) zaupanje 1,0
“Impedance can provide valuable information on cm-1 observed hydroxyl group peaks at 849 as shown in charge transport phenomena in conducting polymer, elec-”
Structural and Electronic Property Study of Polypyrrole Nanowires Synthesized by Electrochemical Method DOI: 10.1166/nnl.2013.1514 -
Silicon-oxygen (Si-O) zaupanje 1,0
“cm-1 cm-1 of SOC and 821 of observed with the band at 849 POXC, representing quartz-like Si-O (Margenot et al., 2020).”
Identifying the fingerprint of permanganate oxidizable carbon as a measure of labile soil organic carbon using Fourier transform mid‐infrared photoacoustic spectroscopy DOI: 10.1111/ejss.13085 -
Alkyl C-H zaupanje 1,0
“CH rocking and wagging are observed at 3 2 -1 849cm-1.The 752 cm and spectrum depicts shift in the wavelength of the vibration bands and also an extra peak at 2355cm-1 .”
Naik 等 - 2019 - Optical and Electrical Properties of TCNQ Doped PM DOI: 10.1063/1.5100466 -
Acetate zaupanje 1,0
“The absorption band near 849 peak C-O-C β (1⟶4)-glycosidic corresponds to symmetric stretching of linkage.”
Influence of size classifications on the crystallinity index of Albizia gummifera cellulose DOI: 10.1016/j.heliyon.2022.e12019 -
Alkyl C-H zaupanje 1,0
“2 Out-of-plane bending vibration of 848.849 C-H in the -CH=CHgroup of 836.955 840.812 blue shift of peak”
Chen 等 - 2013 - Fourier Transform Infrared Spectral Analysis of Po DOI: 10.1155/2013/937284 -
Silicon nitrogen zaupanje 1,0
“cm-1, cm-1, cm-1, 912 and 961 which can be fitted by three symmetric Gaussian bands at 849 represent absorption states of the Si-N stretching mode [52-54].”
Hermann 等 - 2014 - Characterization of semiconductor materials using DOI: 10.1364/OE.22.017948 -
Acetate zaupanje 1,0
“stretching), (C-H bending), 1261 and (C-O 1100-1000cm(cid:3)1 stretching), (C-O stretching in C-O-H groups and 849cm(cid:3)1 observed.20,21 COC groups) and (C-H rocking mode) were”
DSC-FTIR microspectroscopy used to investigate the heat-induced intramolecular cyclic anhydride formation between Eudragit E and PVA copolymer DOI: 10.1038/pj.2011.15; -
Acetate zaupanje 1,0
“C=O to P-O bending (crystalline) and P-O bending (amorphous), associated with C-O (Stretch) and (Stretch) stretching cm-1 cm-1 respectively, presence of C-O stretching at 849 band modes, respectively, and the broad band at about 3710 show t”
Vyas 等 - 2016 - Effect of nickel oxide substitution on bioactivity DOI: 10.1007/s12034-016-1242-7
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