Hvad absorberer ved 1642 cm⁻¹ i et FTIR-spektrum?
Et bånd nær 1642 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 1642 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 | 25 | 22 | 1,0 |
| Water (H2O) | 14 | 13 | 1,0 |
| Hydroxyl (O-H) | 14 | 13 | 1,0 |
| Methacrylate | 11 | 11 | 1,0 |
| Acetate | 11 | 11 | 1,0 |
| Carbonyl (C=O) | 11 | 11 | 1,0 |
| Carboxyl (COOH) | 9 | 8 | 1,0 |
| Ester | 8 | 8 | 1,0 |
| Ketone | 7 | 7 | 1,0 |
| N h | 5 | 4 | 1,0 |
| Alkene (C=C) | 5 | 4 | 1,0 |
| Methoxy (OCH3) | 4 | 4 | 1,0 |
| C-O single bond | 4 | 4 | 1,0 |
| Secondary amine | 4 | 3 | 1,0 |
| Alkyl C-H | 4 | 3 | 1,0 |
| Carbohydrate | 4 | 3 | 1,0 |
| Protein alpha helix | 3 | 3 | 1,0 |
| Chitosan | 3 | 2 | 1,0 |
| C n single bond | 2 | 2 | 1,0 |
| C c single bond | 2 | 2 | 1,0 |
| Aromatic ring | 2 | 2 | 1,0 |
| N n bond | 1 | 1 | 1,0 |
| Acetyl | 1 | 1 | 1,0 |
| Phosphate (PO4) | 1 | 1 | 1,0 |
| Chlorine | 1 | 1 | 1,0 |
| Silicon (Si) | 1 | 1 | 1,0 |
| Silanol (Si-OH) | 1 | 1 | 1,0 |
| Protein random coil | 1 | 1 | 1,0 |
| Protein beta turn | 1 | 1 | 1,0 |
| Lewis acid site | 1 | 1 | 1,0 |
| N-O bond | 1 | 1 | 1,0 |
| Metal oxygen | 1 | 1 | 1,0 |
| Urea | 1 | 1 | 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 |
|---|---|---|---|
| polyethylene | 1642, 1737, 1720 | Methacrylate, Hydroxyl (O-H) | 1 |
| nanocellulose | 1642, 1540, 1646 | Amide, Hydroxyl (O-H), 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 1642 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
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Carbonyl (C=O) tillid 1,0
“~1642cm-1 in all the treated pulp samples may be attributed to release of free carbonyl groups (C=O) due to the action of enzyme on 5.4.”
Exploring the lignolytic potential of a new laccase producing strain Kocuria sp. PBS-1 and its application in bamboo pulp bleaching DOI: 10.1016/j.ibiod.2019.104726 -
Water (H2O) tillid 1,0
“Isothermal rehydration process of preheated raffinose cmK1 8C for 81, 125 or 150 IR peak intensity at 1642 (1641) samples preheated sample was gradually increased with time, due to the 8C, absorption of water vapor from 30 70% RH condition.”
Cheng 和 Lin - 2006 - Processes of dehydration and rehydration of raffin DOI: 10.1016/j.carbpol.2005.11.024 -
Acetate tillid 1,0
“Spectral peaks of FTIR at 1641.79 confirmed the appearance of C--O CO32(cid:0) binding, with strong stretching of in Amide I.”
Biologically-induced synthetic manganese carbonate precipitate (BISMCP) for potential applications in heavy metal removal DOI: 10.1016/j.heliyon.2023.e15919 -
Amide tillid 1,0
“There was a very strong infrared (IR) band at cm-1 1642 generated primarily by the C = O stretching vibration from the amide I of protein in the spectrum (Tatulian, 2013), which overlapped with asymmetric stretching bands from carboxylate.”
Changes in chemical composition and structure of root cell wall of citrus rootstock seedlings in response to boron deficiency by FTIR spectroscopy DOI: 10.1080/14620316.2017.1362327 -
Acetate tillid 1,0
“cm-1 However, peaks are seen at 3479 for SnO 2-doped GO cm-1 cm-1 1639 (C=O stretching vibration), and 1642 (OH”
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
“5 of 23 https://doi.org/10.33263/BRIAC133.274 cm-1 In FTIR spectra, absorption peaks of 1.5% Tylose MH 50 at 3441 and 2835-2906 cm-1 indicated stretching vibrations of OH and symmetric and asymmetric C-H vibrations, cm-1 whereas peaks at 16”
Mustary 等 - 2023 - Synthesis and Characterization of Biocomposite Fil DOI: 10.33263/BRIAC133.274 -
Ester tillid 1,0
“The formed band at region broad peak at 1642 cm(cid:1)1 is attributed to formation of ester groups, which of 1642 is the result of reaction between the hydroxyl group of starch and anhydride groups of coupling agent.”
Physical and thermal mechanical properties of corn starch/LDPE composites DOI: 10.1002/app.37877 -
C c single bond tillid 1,0
“A new peak was detected at 1641.98 in the (C-C-- treated effluent indicating the presence of alkenes C symmetric (C-- stretch), ketones and aldehydes O stretch) (Fig.”
Greenhouse gases emissions from duckweed pond system treating polyester resin wastewater containing 1,4-dioxane and heavy metals DOI: 10.1016/j.ecoenv.2020.111253
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