Hvad absorberer ved 1657 cm⁻¹ i et FTIR-spektrum?
Et bånd nær 1657 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 1657 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 | 36 | 31 | 1,0 |
| Carbonyl (C=O) | 16 | 14 | 1,0 |
| Ester | 10 | 10 | 1,0 |
| Acetate | 10 | 10 | 1,0 |
| Carboxyl (COOH) | 10 | 9 | 1,0 |
| Methacrylate | 9 | 9 | 1,0 |
| Ketone | 9 | 9 | 1,0 |
| Alkyl C-H | 4 | 4 | 1,0 |
| Alkene (C=C) | 4 | 3 | 1,0 |
| Protein | 4 | 2 | 1,0 |
| Secondary amine | 3 | 3 | 1,0 |
| C n single bond | 3 | 3 | 1,0 |
| N h | 3 | 3 | 1,0 |
| Hydrogen bond | 2 | 2 | 1,0 |
| Protein alpha helix | 2 | 2 | 1,0 |
| Aromatic ring | 2 | 2 | 1,0 |
| Protein random coil | 2 | 2 | 1,0 |
| Water (H2O) | 2 | 2 | 1,0 |
| Hydroxyl (O-H) | 2 | 2 | 1,0 |
| Protein beta sheet | 1 | 1 | 1,0 |
| Nitrogen heterocycle | 1 | 1 | 1,0 |
| Nitrile | 1 | 1 | 1,0 |
| C=n | 1 | 1 | 1,0 |
| Quinone | 1 | 1 | 1,0 |
| Ring structure | 1 | 1 | 1,0 |
| Triglyceride | 1 | 1 | 1,0 |
| C c single bond | 1 | 1 | 1,0 |
Rangering afspejler akkumuleret litteraturevidence, ikke en enkelt fast regel. Bekræft altid mod din prøvekontekst.
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 1657 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
-
Hydroxyl (O-H) tillid 1,0
“cm-1 In contrast, the broad peaks at 3405 for SiO was attributed to -OH stretching vibrations whereas 2 cm-1 were assigned to -OH bending vibrations, both of which originated the less prominent peaks at 1657 cm-1 from the silanol (Si-OH) gr”
Nanocellulose-silica polyethersulfone hybrid composite stabilized lipase for esterification DOI: 10.1063/1.5125521 -
Amide tillid 1,0
“Bacillus and Micrococcus can be differfrequency value of the Amide I band was lower (1657.27±1.85) entiated from each other since there were several significant for Bacillus species when compared to Micrococcus species differences between t”
Use of Fourier transform infrared spectroscopy for rapid comparative analysis of Bacillus and Micrococcus isolates DOI: 10.1016/j.foodchem.2008.08.063 -
Carbonyl (C=O) tillid 1,0
“4) comes from the 3-formyl carbonyl stretchingandskeletalC-C/C-Nvibrationalbands.Thedeconvolution of the band showed the presence of the two components at 1657cm-1.”
Morishita 和 Tamiaki - 2009 - Specific coupling between the 13-keto carbonyl and DOI: 10.1016/j.saa.2008.09.016 -
Amide tillid 1,0
“The peaks at 1657 and 1547 (CdO cm-1 are due to the amide I stretch) and amide II”
Noguchi 和 Sugiura - 2002 - Flash-induced FTIR difference spectra of the water DOI: 10.1021/bi011954k -
Amide tillid 1,0
“% and 20 mM Tricin 3 cm-1, amide I and amide II bands at 1657 and 1548 were dissolved without bubbling of CO 2-enriched air.”
Noguchi 和 Sugiura - 2003 - Analysis of flash-induced FTIR difference spectra DOI: 10.1021/bi0341612 -
Ester tillid 1,0
“In the amide I region, a large negative peak around Q peak with weak negative side peaks (Figure 3), suggests that CdO cm-1, appeared at 1674 and the peaks at 1699, 1685, 1664, the effect of Q A/Q reduction on the 10a-ester vibration B cm-1”
Suzuki 等 - 2005 - Fourier transform infrared spectrum of the seconda DOI: 10.1021/bi051237g -
Acetate tillid 1,0
“The spectrum of acesulfame-K (Figure 1) reveals a cm-1, strong band at 1657 corresponding to the C=O Sodium saccharine spectrum (Figure 2) show stretching vibration of the amide group (Amide I”
Tosa 等 - 2012 - Simultaneous Determination Of Some Artificial Swee DOI: 10.1063/1.3681976 -
Amide tillid 1,0
“For Collagen 1654 (2000) 4, the amide I signal is centered around the synthetic peptide LAH Elastin 1655 1657cm-1,andthesignalfortheamideIIispresentat1546cm-1, Humanheartvalve Jastrzebskaetal.”
Vidal 和 Mello - 2011 - Collagen type I amide I band infrared spectroscopy DOI: 10.1016/j.micron.2010.09.010
Har du et spektrum med dette bånd?
Upload dit FTIR-spektrum og få en fuld fortolkningsrapport — peak-tildelinger med litteraturhenvisninger, biblioteksmatch og en litteraturunderstøttet analyse — på få sekunder.