Hvad absorberer ved 1690 cm⁻¹ i et FTIR-spektrum?
Et bånd nær 1690 cm⁻¹ kan pege på flere funktionelle grupper. Nedenfor er de mest sandsynlige tildelinger, rangeret efter hvor meget publiceret bevis der understøtter hver — hver enkelt spores til litteratur (DOI) og krydsvalideres mod vores 130.000+ referencespektre og vidensgraf.
Backed by 8 cited sources
Hurtigt svar
Et bånd nær 1690 cm⁻¹ fortolkes normalt ved at kontrollere, hvilke funktionelle grupper der gentagne gange forekommer der i litteraturen, og derefter bekræfte mindst en eller to yderligere peaks i den samme prøve. Denne side rangerer disse tildelinger efter akkumuleret evidens snarere end efter en enkelt fast lærebogsregel.
Mulige funktionelle gruppetildelinger
| Funktionel gruppe | Understøttende fakta | Citerede kilder | Højeste tillid |
|---|---|---|---|
| Carbonyl (C=O) | 31 | 26 | 1,0 |
| Amide | 29 | 25 | 1,0 |
| Carboxyl (COOH) | 16 | 14 | 1,0 |
| Ester | 13 | 11 | 1,0 |
| Methacrylate | 12 | 10 | 1,0 |
| Acetate | 12 | 10 | 1,0 |
| Ketone | 11 | 9 | 1,0 |
| Protein | 6 | 5 | 1,0 |
| N h | 5 | 5 | 1,0 |
| Protein beta sheet | 5 | 5 | 1,0 |
| Alkene (C=C) | 5 | 4 | 1,0 |
| Hydroxyl (O-H) | 5 | 4 | 1,0 |
| Alkyl C-H | 4 | 4 | 1,0 |
| Protein beta turn | 3 | 3 | 1,0 |
| Secondary amine | 3 | 2 | 1,0 |
| N-O bond | 3 | 2 | 1,0 |
| Aromatic ring | 3 | 1 | 1,0 |
| Methoxy (OCH3) | 2 | 2 | 1,0 |
| C-O single bond | 2 | 2 | 1,0 |
| C n single bond | 2 | 1 | 1,0 |
| Water (H2O) | 2 | 1 | 1,0 |
| Ring structure | 2 | 1 | 1,0 |
| Phosphate (PO4) | 1 | 1 | 1,0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1,0 |
| Silicon (Si) | 1 | 1 | 1,0 |
| Hydrogen bond | 1 | 1 | 1,0 |
| C-S single bond | 1 | 1 | 1,0 |
| Protein alpha helix | 1 | 1 | 1,0 |
| C=n | 1 | 1 | 1,0 |
| Urea | 1 | 1 | 1,0 |
| Adsorbed carbon monoxide | 1 | 1 | 1,0 |
| Imide | 1 | 1 | 0,9 |
| Carbonate | 1 | 1 | 0,8 |
Rangering afspejler akkumuleret litteraturevidence, ikke en enkelt fast regel. Bekræft altid mod din prøvekontekst.
Mulige materialer
| Materiale | Understøttende toppe | Overlappende grupper | Citerede kilder |
|---|---|---|---|
| chitosan | 1690, 1650, 1655 | Amide | 1 |
| polyurethane | 1690, 2270, 1700 | Carbonyl (C=O), Amide | 1 |
| polycaprolactone | 1690, 1580, 1751 | Carbonyl (C=O), Amide, Ester | 1 |
Materialer vises kun, når den samme litteraturpulje understøtter dette bånd og mindst en yderligere karakteristisk top.
Spektrumlogik
Dette bånd bliver meningsfuldt kun, når det læses sammen med sine nabotoppe. I praksis ser analytikere først på tildelingerne ovenfor, og kontrollerer derefter, om den samme prøve også viser andre toppe, der forventes for det samme strukturelle motiv. Et enkelt bånd nær 1690 cm⁻¹ er normalt ikke nok til materialeidentifikation alene.
Anvendelse i virkeligheden
Denne type forespørgsel er almindelig ved polymeridentifikation, screening af ukendt plast, fejlfinding i kvalitetskontrol, verifikation af genanvendt materiale og litteraturunderstøttet gennemgang af peak-tildeling.
Almindelige fejl
- Behandling af et isoleret bånd som bevis på et materiale uden at kontrollere mindst en eller to understøttende toppe.
- Ignorerer overlap: flere funktionelle grupper kan bidrage nær samme bølgetal.
- Spring validering over, når additiver, blandinger, oxidation eller forurening kan forvrænge spektret.
Verifikationsrådgivning
Når tvetydighed fortsat består, valider hypotesen med DSC, GC-MS eller TGA, især for blandinger, nedbrudte prøver og fyldte polymerer.
Litteratur bag disse tildelinger
-
Alkene (C=C) tillid 1,0
“The peaks at 1690 and 3691 correspond to C=C and N-H vibrations cm-1 respectively.”
Highly Biological Active Antibiofilm, Anticancer and Osteoblast Adhesion Efficacy from MWCNT/PPy/Pd nanocomposite DOI: 10.1016/j.apsusc.2017.10.142 -
Protein beta turn tillid 1,0
“Peaks between 1690 and 1665 are generally assigned to β-turn structures.”
Fevzioglu 等 - 2020 - Quantitative approach to study secondary structure DOI: 10.1016/j.ijbiomac.2020.07.299 -
Adsorbed carbon monoxide tillid 1,0
“This is based on our assignment of the 1690 band in the commercial Au/TiO catalyst DRIFT spectrum actually being 2 bridging CO between two Au atoms.”
Gaur 等 - 2013 - CO oxidation studies over cluster-derived AuTiO2 DOI: 10.1016/j.cattod.2012.10.029 -
Urea tillid 1,0
“1690cm-1 absence of peaks at The PU was cast onto the screen-printed electrode (SPE) representing urea (C=O) in and analyzed using a single voltammetric cycle between this study indicated there is no urea formation as a bypro- -1200 and +15”
Munir 等 - 2022 - Design and Synthesis of Conducting Polymer Bio-Bas DOI: 10.1155/2022/6815187 -
Carbonyl (C=O) tillid 1,0
“In the literature, FTIR analysis of natural resins featured broad hycm(cid:2)1, droxyl stretch at around 3400 strong carbonyl stretch at 1690cm(cid:2)1, cm(cid:2)1, C¼C 1740 weak signal of vibrations at about 1610 methyl cm(cid:2)1,”
Geographical variations and correlation among some chemical and thermal properties of Almaciga (Agathis philippinensis Warb.) resins from selected commercial sites in the Philippines DOI: 10.1016/j.heliyon.2021.e06413 -
tillid 1,0
“FTIR absorption peak cm-1 at around 1690 was attributed to the bending vibration of N-H from PEI.”
Plasma-Induced Graft Polymerization of Polyethylenimine onto Chitosan/Polycaprolactone Composite Membrane for Heavy Metal Pollutants Treatment in Industrial Wastewater DOI: 10.3390/coatings12121966 -
Protein tillid 1,0
“(1985) PolyprolineIIdriedfilm 1640 The methods for processing mineralized tissues for FT-IR have PolyprolineIIafterheating 1650 1660cm-1/1690cm-1 used a peak of area ratio to detect collagen (Gly-Pro-Ala)n 1630,1656 inD2Osolution maturation”
Vidal 和 Mello - 2011 - Collagen type I amide I band infrared spectroscopy DOI: 10.1016/j.micron.2010.09.010 -
Carbonyl (C=O) tillid 1,0
“To clarify in 2O, should also be visible but was overlapped by the H 2 cm(cid:2)1.[20] which steps O strong carbonyl absorption at 1690 is incorporated into the product acids, we Other spectra in 2 further examined the possible intermediate”
An Unexplored O2Involved Pathway for the Decarboxylation of Saturated Carboxylic Acids by TiO2 Photocatalysis: An Isotopic Probe Study DOI: 10.1002/chem.201001704
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