Hvad absorberer ved 1236 cm⁻¹ i et FTIR-spektrum?
Et bånd nær 1236 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 1236 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 |
|---|---|---|---|
| Acetate | 17 | 16 | 1,0 |
| Amide | 16 | 16 | 1,0 |
| Methacrylate | 16 | 16 | 1,0 |
| C-O single bond | 15 | 15 | 1,0 |
| Methoxy (OCH3) | 14 | 14 | 1,0 |
| Alkyl C-H | 7 | 5 | 1,0 |
| Secondary amine | 5 | 5 | 1,0 |
| C n single bond | 5 | 5 | 1,0 |
| Phosphate (PO4) | 5 | 4 | 1,0 |
| Ester | 4 | 4 | 1,0 |
| Carboxyl (COOH) | 4 | 3 | 1,0 |
| Hydroxyl (O-H) | 3 | 3 | 1,0 |
| Phosphorus | 3 | 2 | 1,0 |
| Nucleic acid | 2 | 2 | 1,0 |
| Ketone | 2 | 2 | 1,0 |
| Carbonyl (C=O) | 2 | 2 | 1,0 |
| N h | 1 | 1 | 1,0 |
| Hydrogen bond | 1 | 1 | 1,0 |
| Fluorine (C-F) | 1 | 1 | 1,0 |
| Carbohydrate | 1 | 1 | 1,0 |
| Lignin | 1 | 1 | 1,0 |
| Aromatic ring | 1 | 1 | 1,0 |
| Phospholipid | 1 | 1 | 1,0 |
| Protein beta sheet | 1 | 1 | 1,0 |
| Acetyl | 1 | 1 | 1,0 |
| Methyl | 1 | 1 | 0,8 |
| Silicon-oxygen (Si-O) | 1 | 1 | 0,6 |
Rangering afspejler akkumuleret litteraturevidence, ikke en enkelt fast regel. Bekræft altid mod din prøvekontekst.
Mulige materialer
| Materiale | Understøttende toppe | Overlappende grupper | Citerede kilder |
|---|---|---|---|
| methylene blue | 1236, 1745, 1739 | Methacrylate, Acetate, Amide | 1 |
| cellulose nanocrystals | 1236, 1110, 1640 | Acetate, Methacrylate, C-O single bond | 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 1236 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
-
Phosphate (PO4) tillid 1,0
“0.14 0.01** Amide II 1542.34±1.54 1545.34±0.46 0.05* COO symmetric stretching 1396.38±2.09 1398.45±1.27 0.01** PO2 asymmetric stretching 1235.51±1.74 1250.20±0.57 0.01** C-O-C symmetric stretching 1156.29±1.22 1150.96±1.48 PO2 symmetric str”
Use of Fourier transform infrared spectroscopy for rapid comparative analysis of Bacillus and Micrococcus isolates DOI: 10.1016/j.foodchem.2008.08.063 -
Acetate tillid 1,0
“cm-1 in the spectrum of MB with 1664 this significantly sharp and strong peak at 1599 in thatofthemetabolites suggested theformationof carboxylgroups;the presenceof1082and 1236cm-1 peaks, associated with C-O stretching vibration,substantiat”
Biodegradation of Methylene Blue as an Evidence of Synthetic Dyes Mineralization during Textile Effluent Biotreatment by Acinetobacter pittii DOI: 10.1007/s40710-020-00443-6 -
Amide tillid 1,0
“In the Figure 1, in amide I vibrational region, are and 1236 respectively.”
Structural analysis of some soluble elastins by means of FTIR and 2D IR correlation spectroscopy DOI: 10.1002/bip.21524 -
Acetate tillid 1,0
“cm-1 Meanwhile, the peak at 1236 in raw TLWF spectrum is attributed to the C-O stretching vibration [26].”
Extraction and Characterization of Cellulose Nanocrystals from Tea Leaf Waste Fibers DOI: 10.3390/polym9110588 -
Amide tillid 1,0
“cm-1), cm-1), cm-1), (1450.65 C-N stretching (1394.53 amide III or C-N stretching (1235.67 CO-O-C cm-1), cm-1) symmetric stretching vibration (1073.59 stretching vibration of C-O groups ( 928.78 and”
Encapsulation of olive leaf phenolics within electrosprayed whey protein nanoparticles; production and characterization DOI: 10.1016/j.foodhyd.2019.105572 -
Alkyl C-H tillid 1,0
“A band observed at 1236 entails the antisymmetric C-H in-plane bending”
Velhal 等 - 2018 - Structural, electrical and microwave properties of DOI: 10.1088/2053-1591/aadaf7 -
Acetate tillid 1,0
“The absorption peak at 1236 of the pyrimidine ring, the out-of-plane swinging of the C O tortion cm-1is characterized by molecular vibrations, including the distorbonds, and the stretching and swinging of the C H and N H bonds.”
A comparative study on the experimental and calculated results of mid-infrared and Raman vibrational modes of nucleic acid bases DOI: 10.1016/j.jmgm.2017.04.016 -
Amide tillid 1,0
“[46], the peak at 1145 the amide band that accounts for the peak at 1236 cm-1[45].”
Antibacterial Activity of the Green Synthesized Plasmonic Silver Nanoparticles with Crystalline Structure against Gram-Positive and Gram-Negative Bacteria DOI: 10.3390/nano13081327
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