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
Ātra atbilde
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.
Iespējamie funkcionālo grupu piešķīrumi
| Funkcionālā grupa | Atbalstošie fakti | Citētie avoti | Augstākā pārliecība |
|---|---|---|---|
| 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 |
Rangs atspoguļo uzkrātos literatūras pierādījumus, nevis vienu autoritatīvu noteikumu. Vienmēr apstipriniet atbilstoši parauga kontekstam.
Iespējamie materiāli
| Materiāls | Atbalstošie pīķi | Pārklājošās grupas | Citētie avoti |
|---|---|---|---|
| PVA | 849, 1660, 2930 | Acetate, Methacrylate, C-O single bond | 1 |
| Polypyrrole | 849, 1700, 400 | Methacrylate, Acetate | 1 |
Materiāli tiek parādīti tikai tad, ja šo joslu un vismaz vienu papildu raksturīgo pīķi atbalsta tā pati literatūras kopa.
Spektra loģika
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.
Reālās pasaules izmantošana
Šāda veida vaicājums ir izplatīts polimēru identificēšanā, nezināmas plastmasas skrīningā, kvalitātes kontroles problēmu risināšanā, pārstrādāto materiālu pārbaudē un ar literatūru pamatotā pīķu piešķīruma pārskatā.
Biežākās kļūdas
- Vienas izolētas joslas uzskatīšana par materiāla pierādījumu, nepārbaudot vismaz vienu vai divus atbalsta pīķus.
- Ignorējot pārklāšanos: vairākas funkcionālās grupas var dot ieguldījumu tuvu tam pašam viļņa skaitlim.
- Izlaist validāciju, ja piedevas, maisījumi, oksidācija vai piesārņojums var izkropļot spektru.
Verifikācijas padoms
Ja joprojām pastāv neskaidrība, apstipriniet hipotēzi ar DSC, GC-MS vai TGA, īpaši maisījumiem, noārdītiem paraugiem un pildītiem polimēriem.
Literatūra aiz šiem piešķīrumiem
-
Hydroxyl (O-H) pārliecība 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) pārliecība 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 pārliecība 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 pārliecība 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 pārliecība 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 pārliecība 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 pārliecība 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 pārliecība 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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