What absorbs at 847 cm⁻¹ in an FTIR spectrum?
A band near 847 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
Snabbt svar
A band near 847 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.
Möjliga identifieringar av funktionella grupper
| Funktionell grupp | Stödjande fakta | Citerade källor | Högsta förtroende |
|---|---|---|---|
| Alkyl C-H | 2 | 2 | 1,0 |
| Silicon carbon | 2 | 1 | 1,0 |
| Carbohydrate | 1 | 1 | 1,0 |
| Ring structure | 1 | 1 | 1,0 |
| Nucleic acid | 1 | 1 | 1,0 |
| Silanol (Si-OH) | 1 | 1 | 1,0 |
| Silicon (Si) | 1 | 1 | 1,0 |
| Methacrylate | 1 | 1 | 1,0 |
| Ketone | 1 | 1 | 1,0 |
| Ester | 1 | 1 | 1,0 |
| Carboxyl (COOH) | 1 | 1 | 1,0 |
| Carbonyl (C=O) | 1 | 1 | 1,0 |
| Amide | 1 | 1 | 1,0 |
| Acetate | 1 | 1 | 1,0 |
| Metal oxygen | 1 | 1 | 1,0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1,0 |
| C-O single bond | 1 | 1 | 0,9 |
| Sulfate (SO4) | 1 | 1 | 0,9 |
Rankingen speglar ackumulerade litteraturbevis, inte en enda auktoritativ regel. Bekräfta alltid mot din provkontext.
Möjliga material
| Material | Stödjande toppar | Överlappande grupper | Citerade källor |
|---|---|---|---|
| PMMA | 847, 1722, 1383 | Alkyl C-H | 1 |
| Alginate | 847, 1100, 1715 | Alkyl C-H | 1 |
| SiO2 | 847, 1739, 699 | Alkyl C-H | 1 |
| TiO2 | 847, 1700, 1093 | Alkyl C-H | 1 |
| PVA | 847, 1660, 2930 | Alkyl C-H | 1 |
| sodium alginate | 847, 1636, 1080 | Alkyl C-H | 1 |
Material visas endast när samma litteraturpool stöder detta band och minst en ytterligare karakteristisk topp.
Spektrumlogik
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 847 cm⁻¹ is usually not enough for material identification by itself.
Användning i verkligheten
Denna typ av fråga är vanlig inom polymeridentifiering, screening av okänd plast, felsökning av kvalitetskontroll, verifiering av återvunnet material och litteraturstödd toppidentifieringsgranskning.
Vanliga misstag
- Behandla ett isolerat band som bevis på ett material utan att kontrollera minst en eller två stödjande toppar.
- Ignorerar överlapp: flera funktionella grupper kan bidra nära samma vågtal.
- Hoppa över validering när tillsatser, blandningar, oxidation eller föroreningar kan förvränga spektrat.
Verifieringsråd
När oklarhet kvarstår, validera hypotesen med DSC, GC-MS eller TGA, särskilt för blandningar, nedbrutna prover och fyllda polymerer.
Litteratur bakom dessa identifieringar
-
förtroende 1,0
“847cm-1, (1635cm-1), 470-481cm-1, hygroscopic water Si-O vibrations 1100, 611-621, etc.”
Cai 等 - 2007 - A Fourier transform infrared spectroscopic study o DOI: 10.1016/j.saa.2006.02.053 -
Silicon carbon förtroende 1,0
“1239.2 and 1087.8 Si-OH 953.7 Symmetric Si-O-Si stretching 797.5 Si-O-Si bending 458.1 C-H stretching of trimetylsilyl 2970 - 2850 Si-C stretching 846.7 and 758.9 The intensity of band characteristic of C=O groups for all cases was increase”
Nurul 等 - 2012 - XRD, FTIR and C-13 CPMAS NMR Studies of Composite DOI: 10.4028/www.scientific.net/AMR.364.159 -
Alkyl C-H förtroende 1,0
“1244cm-1, The peak at assigned to the CH-rocking vibrationofPVCinPVC-PMMAblendisobservedtohaveshiftedto 847cm-1 1256cm-1 1438, 1168, 988 and are shifted to 2874, 1734, 1460, in the PVC-PMMA-LiCF 3SO complex.”
Ramesh 等 - 2007 - FTIR studies of PVCPMMA blend based polymer elect DOI: 10.1016/j.saa.2006.06.012 -
Metal oxygen förtroende 1,0
“The bands observed around 847 and 601 belong to the 2 cm-1 asymmetric stretching of Ti-O-Ti groups.”
Sathish 等 - 2013 - Nano Composite PVA-TiO2 Thin Films for OTFTs DOI: 10.4028/www.scientific.net/AMR.678.335 -
Acetate förtroende 1,0
“7, spectrum a) displays the presence of epoxide FTIR bands positioned at 997, 910 and cm-1, cm-1, 847 the C=O band at 1,734 as well as the”
Structural, morphological and mechanical characteristics of polyethylene, poly(lactic acid) and poly(ethylene-co-glycidyl methacrylate) blends DOI: 10.1007/s13726-013-0126-6 -
Silicon (Si) förtroende 1,0
“The bands at 864 cm-1 and 847 cm-1 that were not present in D4 and VTES spectra and increased in the course of the reaction could be attributed to Si-OH in -Si(CH3)2-OH and in -Si (O) (CH=CH2)-OH, respectively.”
Cationic Emulsion Polymerization of Octamethylcyclotetrasiloxane (D4) in Mixtures with Alkoxysilanes DOI: 10.3390/xxxxx -
Alkyl C-H förtroende 1,0
“LLM confirmed rule peak-group candidate”
The Effect of Pollutant Gases on Surfactant Migration in Acrylic Emulsion Films: A Comparative Study and Preliminary Evaluation of Surface Cleaning DOI: 10.3390/polym13121941 -
Nucleic acid förtroende 1,0
“Two negative bands at 1077 and 717 also contributed to the vibrations cm-1 of phospholipids and nucleic acids, and the positive band at 847 contributed to the C1αH bending of glycogen.”
Ex Vivo Vibration Spectroscopic Analysis of Colorectal Polyps for the Early Diagnosis of Colorectal Carcinoma DOI: 10.3390/diagnostics11112048
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