Hvad absorberer ved 702 cm⁻¹ i et FTIR-spektrum?
Et bånd nær 702 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 702 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 |
|---|---|---|---|
| Alkyl C-H | 3 | 3 | 1,0 |
| Aromatic ring | 2 | 2 | 1,0 |
| N h | 1 | 1 | 1,0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1,0 |
| Silicate | 1 | 1 | 1,0 |
| Metal oxygen | 1 | 1 | 1,0 |
| Methoxy (OCH3) | 1 | 1 | 1,0 |
| Methacrylate | 1 | 1 | 1,0 |
| C-O single bond | 1 | 1 | 1,0 |
| Acetate | 1 | 1 | 1,0 |
| Hydroxyl (O-H) | 1 | 1 | 1,0 |
| Carboxyl (COOH) | 1 | 0 | 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 702 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
-
tillid 1,0
“The band at 996 is assigned to V O stretching of distorted octahedral and distorted cm-1 square pyramids, while the band at 702 is due to coordination of vanadium atoms with the three oxygen”
Vanadium pentoxide nanobelts: One pot synthesis and its lithium storage behavior DOI: 10.1002/crat.201200122 -
Hydroxyl (O-H) tillid 1,0
“cm-1 (Figure S6b), respectively The band at 702 is influenced by three modes of vibration: μ 3cm-1 OH bending + O-C-O bending + C=C-(COO) bending, while the one at 729 corresponds to 13.”
Iodine Uptake by Zr/Hf-Based UiO-66 Materials: The Influence of Metal Substitution on Iodine Evolution DOI: 10.1016/S0167-8140(02)00374-2. -
tillid 1,0
“The band observed at cm-1 702 corresponded to the Ti-O stretching and Ti-O-Ti bridging stretching bonds [30,31];”
Camila Ariza-Tarazona 等 - 2019 - New strategy for microplastic degradation Green p DOI: 10.1016/j.ceramint.2018.10.208 -
Silicate tillid 1,0
“Silicates are represented by the intense peaks at 1989 and 1871 cm-1 [66], and by the specific peaks of quartz at 2236, 2132 and 702 cm-1, and those attributed to muscovite at”
Technological and Functional Approaches Applied to Miniature Vessels with Pigment Traces: Two Middle Bronze Age Case Studies from Eastern Subcarpathians of Romania DOI: 10.3390/app13042093 -
Alkyl C-H tillid 1,0
“cm-1 C-H out-of-plane bending modes at 702 and 761 When a weak peak is present at 3083 and cm-1 a more intense peak at 1599 can be detected, the occurrence of a copolymer of styrene and αmethyl-styrene was suggested.”
Germinario 等 - 2016 - Chemical characterisation of spray paints by a mul DOI: 10.1016/j.microc.2015.04.016 -
Aromatic ring tillid 1,0
“The FTIR spectrum of CIN showed principle -1 -1 The results of the assay indicated that the content in the var- -H absorption peaks at 702.04 cm and 748.33 cm (C bending -1 -1 ious solid systems prepared by different methods was in the -H o”
Multicomponent cyclodextrin system for improvement of solubility and dissolution rate of poorly water soluble drug DOI: 10.1016/j.ajps.2018.02.007 -
tillid 1,0
“The medium strength vibrational band present at 702 The role of FTIR spectroscopy in the clinical analysis of - 1 is assigned to N-H out of plane bending with the cm normal and diabetic blood samples is clearly demonstrated.”
Ramalingam 等 - 2014 - Evaluation of metformin hydrochloride in Wistar ra DOI: 10.4103/0976-9668.136168 -
Alkyl C-H tillid 1,0
“The band at 702 cm is likely due to overlapping peaks of the CH rocking vibration and the out-of-plane vibration of cis-disubstituted 2 olefins, related to the presence of long chain hydrocarbons [108].”
Stefanov 等 - 2013 - Towards combinatorial spectroscopy The case of mi DOI: 10.30744/brjac.2179-3425.2018.5.18.12-27
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