What absorbs at 781 cm⁻¹ in an FTIR spectrum?
A band near 781 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
Përgjigje e shpejtë
A band near 781 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.
Caktime të mundshme të grupeve funksionale
| Grup funksional | Fakte mbështetëse | Burimet e cituara | Besueshmëri e lartë |
|---|---|---|---|
| Siloxane (Si-O-Si) | 2 | 2 | 1,0 |
| Silicon-oxygen (Si-O) | 2 | 2 | 1,0 |
| Silicon (Si) | 2 | 2 | 1,0 |
| Aromatic ring | 2 | 2 | 1,0 |
| Nucleic acid | 1 | 1 | 1,0 |
| Ring structure | 1 | 1 | 1,0 |
| C c single bond | 1 | 1 | 1,0 |
| Oxalate | 1 | 1 | 1,0 |
| Alkyl C-H | 1 | 1 | 1,0 |
| Secondary amine | 1 | 1 | 1,0 |
| C n single bond | 1 | 1 | 1,0 |
| Amide | 1 | 1 | 1,0 |
| Chlorine | 1 | 1 | 1,0 |
Renditja pasqyron provat e grumbulluara të literaturës, jo një rregull të vetëm autoritar. Gjithmonë konfirmoni në kontekstin e mostrës suaj.
Logjika e spektrit
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 781 cm⁻¹ is usually not enough for material identification by itself.
Përdorimi në botën reale
Ky lloj pyetjeje është i zakonshëm në identifikimin e polimereve, skriningun e plastikës së panjohur, zgjidhjen e problemeve të kontrollit të cilësisë, verifikimin e materialeve të ricikluara dhe rishikimin e caktimit të pikut të mbështetur nga literatura.
Gabimet e zakonshme
- Trajtimi i një brezi të izoluar si provë e një materiali pa kontrolluar të paktën një ose dy pika mbështetëse.
- Duke injoruar mbivendosjen: grupe të shumta funksionale mund të kontribuojnë afër të njëjtit numër valor.
- Kalimi i vërtetimit kur aditivët, përzierjet, oksidimi ose ndotja mund të shtrembërojnë spektrin.
Këshillë për verifikim
Kur mbetet paqartësi, verifiko hipotezën me DSC, GC-MS ose TGA, veçanërisht për përzierjet, mostrat e degraduara dhe polimerët e mbushur.
Literatura pas këtyre caktimeve
-
Silicon (Si) besueshmëri 1,0
“The cm-1 cm-1 absorption band at 781 and 1050 are assigned to the v 1symmetric vibration and v 3asymmetrical stretching vibration of the Si-O bond.”
Ilmi 等 - 2020 - Multi-analytical characterizations of prehistoric DOI: 10.1016/j.microc.2020.104738 -
besueshmëri 1,0
“cm-1, The spectra produced strong peaks at 521.38 and 516.39 corresponding to the C-I (stretching) functional group of alkyl halides, for the leaf and stem, respectively, as well as cm-1 a strong peak corresponding to the C-Cl (stretching)”
Phytochemical Composition of Combretum molle (R. Br. ex G. Don.) Engl. & Diels Leaf and Stem Extracts DOI: 10.3390/plants12081702 -
Alkyl C-H besueshmëri 1,0
“Both samples treated with TEMPO derivatives show the characteristic signals of their functional groups: in particular, the band at 1709 and 1717 cm-1 can be associated with the cm-1 functional groups: in particular, the band at 1709 and 171”
Cicogna 等 - 2022 - Surface Functionalization of Face Masks with Cold DOI: 10.3390/molecules27238632 -
Oxalate besueshmëri 1,0
“The FTIR spectrum peaks at 780.7, 1336.4, and 1631.0 all correspond to reported peak positions for sodium oxalate [16].”
Evaluation of Formate Salt PCM’s for Latent Heat Thermal Energy Storage DOI: 10.3390/en14030765 -
besueshmëri 1,0
“The vibrational band centred at 781 cm-1 is ascribed to the stretching mode modes due to the formation of nonbridge oxygen.”
Effect of Yb3+ on the Structural and Visible to Near-Infrared Wavelength Photoluminescence Properties in Sm3+-Yb3+-Codoped Barium Fluorotellurite Glasses DOI: 10.3390/ma15093314 -
C c single bond besueshmëri 1,0
“Furthermore, for the spectrum of cm-1 1545, and 1552 cm-1, respectively, can be attributed to the C-C stretching vibration of benzene ring HACSa, HACCa, HACPc, and HACGa, absorption peaks at 781, 767, 772, 735, 739 corresponded 1478cm-1 [3,”
Modification of Hydroxypropyltrimethyl Ammonium Chitosan with Organic Acid: Synthesis, Characterization, and Antioxidant Activity DOI: 10.3390/polym12112460 -
Silicon (Si) besueshmëri 1,0
“The peaks at 113 cm-1 cm-1 876 cm-1 and 781 cm-1 were assigned to Si-O-Si symmetric stretching vibrations [36].”
Adsorption of Hexavalent Chromium Using Banana Pseudostem Biochar and Its Mechanism DOI: 10.3390/su10114250 -
Nucleic acid besueshmëri 1,0
“LLM confirmed rule peak-group candidate”
Zelig 等 - 2010 - Biochemical analysis and quantification of hematop DOI: 10.1117/1.3442728(cid:4)
Keni një spektër me këtë brez?
Ngarkoni spektrin tuaj FTIR dhe merrni një raport të plotë interpretimi — caktim i pikut me citime literaturë, përputhje biblioteke dhe një zinxhir provash të vlerësuar me besueshmëri — në sekonda.