Hvad absorberer ved 1639 cm⁻¹ i et FTIR-spektrum?
Et bånd nær 1639 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 1639 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 |
|---|---|---|---|
| Amide | 38 | 35 | 1,0 |
| Carbonyl (C=O) | 20 | 19 | 1,0 |
| Methacrylate | 17 | 17 | 1,0 |
| Acetate | 17 | 17 | 1,0 |
| Carboxyl (COOH) | 16 | 16 | 1,0 |
| Water (H2O) | 15 | 14 | 1,0 |
| Hydroxyl (O-H) | 14 | 14 | 1,0 |
| Ketone | 14 | 14 | 1,0 |
| Ester | 14 | 14 | 1,0 |
| Alkene (C=C) | 13 | 10 | 1,0 |
| Protein beta sheet | 7 | 7 | 1,0 |
| N h | 6 | 6 | 1,0 |
| Secondary amine | 6 | 6 | 1,0 |
| Alkyl C-H | 5 | 5 | 1,0 |
| Methoxy (OCH3) | 4 | 4 | 1,0 |
| C-O single bond | 4 | 4 | 1,0 |
| Protein | 4 | 4 | 1,0 |
| Aromatic ring | 4 | 4 | 1,0 |
| C n single bond | 4 | 4 | 1,0 |
| Protein random coil | 3 | 3 | 1,0 |
| Protein alpha helix | 2 | 2 | 1,0 |
| C c single bond | 2 | 2 | 1,0 |
| Urea | 2 | 2 | 1,0 |
| Hydrogen bond | 1 | 1 | 1,0 |
| Methyl | 1 | 1 | 1,0 |
| Urethane | 1 | 1 | 1,0 |
| Amine primary | 1 | 1 | 1,0 |
| Thiol | 1 | 1 | 1,0 |
| Nitro (NO2) | 1 | 1 | 1,0 |
| Isocyanate | 1 | 1 | 1,0 |
| Ring structure | 1 | 0 | 1,0 |
| Nitrogen heterocycle | 1 | 0 | 1,0 |
| Lipid | 1 | 0 | 1,0 |
| N n bond | 1 | 0 | 1,0 |
Rangering afspejler akkumuleret litteraturevidence, ikke en enkelt fast regel. Bekræft altid mod din prøvekontekst.
Mulige materialer
| Materiale | Understøttende toppe | Overlappende grupper | Citerede kilder |
|---|---|---|---|
| TiO | 1639, 1730, 1699 | Methacrylate, Acetate | 1 |
| hydroxyapatite | 1639, 1620, 1630 | Methacrylate, Acetate, Amide | 1 |
| protein | 1639, 1650, 1640 | Amide, Carbonyl (C=O), Methacrylate | 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 1639 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
-
Water (H2O) tillid 1,0
“It relaxometry were for the first time combined to NMR T 2 cm-1 may also is important to point out that the band at 1639 facilitate a simultaneous characterization of protein structures be due to water remaining in the tissue sections after”
Bertram 等 - 2006 - Heat-induced changes in myofibrillar protein struc DOI: 10.1021/jf0514726 -
Acetate tillid 1,0
“Aliphatic CH stretching was observed as two peaks at 2943 and 2885 and and the peak at 1639 cm-1 indicates the stretching vibration of C=O.”
Bio_Fabricated Levan Polymer from Bacillus subtilis MZ292983.1 with Antibacterial, Antibiofilm, and Burn Healing Properties DOI: 10.3390/app12136413 -
Acetate tillid 1,0
“2 cm-1 cm-1, 1639 C=O stretching band vibration, 1494 1011 cm-1 cm-1 cm-1 bands, 733 bands, and 438 bands were”
Reactive Oxygen Species (ROS) Are Generated as Organic Contaminants Are Broken Down: SnO DOI: 10.1007/s12668-023-01111-3 -
Hydroxyl (O-H) tillid 1,0
“Meanwhile, for the SLN spectrum, cm-1 the absorption peak centered at 3420 corresponds -C-OH stretching vibration, and weak cm-1 represent C=C stretching vibration, -OH absorption peaks at 1639, 1370 and 1090 deformation vibration and -C-O”
Kim 和 Kang - 2012 - Fabrication of large area photonic crystal with su DOI: 10.1117/12.930432 -
Carbonyl (C=O) tillid 1,0
“Small band at 1639 belongs to carbonyl (-C=O) with C=O-NH arrangements of traces of urea which may be present due to the reaction of excess isocyanate with moisture in air.”
Preparation and characterization of aliphatic polyurethane and modified hydroxyapatite composites for bone tissue engineering DOI: 10.1007/s00289-019-03067-5 -
C c single bond tillid 1,0
“(1687/1643→1663/1639cm-1, C-C/C-N vibration see middle of Change of the solvent from CH 2Cl to CCl slightly affected the”
Morishita 和 Tamiaki - 2009 - Specific coupling between the 13-keto carbonyl and DOI: 10.1016/j.saa.2008.09.016 -
Amide tillid 1,0
“We demonstrated that the binding of the antibody to the antigen cm-1), immobilized on a GaAs surface selectively gave rise to (cid:226)-sheet amide I vibrations (1639 and 1690 while no structurally related signals were induced by nonspecifi”
Onodera 等 - 2007 - Label-free detection of protein-protein interactio DOI: 10.1021/la7022192 -
Alkene (C=C) tillid 1,0
“In contrast 0.0 cm-1, to untreated TiO, a strong peak at 1300 -80 -60 -40 -20 0 20 assignable to the Ti-O stretching vibrations, peak at Zeta Potential (mV) cm-1, assignable to the C=O stretching vibrations, 474 3: Zeta potential of TiO nan”
Singh 等 - 2016 - FT-IR and Zeta Potential Measurements on TiO Nanop DOI: 10.1063/1.4948233
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