Alkene (C=C) — FTIR-absorptions-toppe og tildelinger

Hurtigt svar

Alkene (C=C) tildeles normalt ved at lede efter en tilbagevendende klynge af karakteristiske toppe frem for et præcist lærebogsnummer. Tabellen nedenfor viser, hvor litteraturen oftest placerer denne gruppe i FTIR, rangeret efter akkumuleret evidens.

Karakteristiske FTIR-toppe for Alkene (C=C)

Viser de 30 bedst understøttede toppe ud af 804 i alt for Alkene (C=C).

Spektrumlogik

En funktionel gruppetildeling bliver mere sikker, når flere forventede bånd optræder sammen. Brug denne side til at finde de bedst understøttede peaks, og bekræft derefter, at den samme prøve udviser et sammenhængende mønster snarere end et enkelt isoleret hit.

Anvendelse i virkeligheden

Disse sider er nyttige til analyse af ukendte materialer, topforklaring i rapporter, polymerfejlfinding og verifikation af, om en kandidatmaterialefamilie er kemisk plausibel.

Almindelige fejl

• Brug af én funktionel-gruppe-side som en komplet materialebedømmelse uden at kontrollere resten af spektret.
• Antager, at det stærkeste bånd altid er det mest diagnostiske.
• At glemme, at forarbejdning, tilsætningsstoffer, ældning og blandinger kan flytte eller udvide forventede toppe.

Verifikationsrådgivning

Brug DSC, GC-MS eller TGA, når flere materialefamilier deler lignende bånd, eller når blandings-effekter gør FTIR-tildelingen usikker.

Litteratur bag disse tildelinger

• 968 cm⁻¹ tillid 1,0

  “and quantified by using Fourier-transform infrared (FTIR) spectroscopy, in the mid-region of 400-4000 cm-1, The FTIR analysis shows that two oil extracts (with and without heat) present a well-defined peak at 968 which represents the double”

  Ariza Ortega 等 - 2012 - Analysis of trans fatty acids production and squal DOI: 10.2478/s11532-012-0104-4
• 1535 cm⁻¹ tillid 1,0

  “LLM confirmed rule peak-group candidate”

  Arizka 等 - 2019 - Synthesis and Physical Properties Characterization DOI: 10.1088/1757-899X/546/4/042004
• 1643 cm⁻¹ tillid 1,0

  “cm-1 peak at 1705.1 means that there is a bond of cm-1 -C=O, and also absorption at 1643.4 and medium intensity which shows the presence of C=C.”

  Aritonang 等 - 2019 - Grafting of Oleic Acid On Cyclic Natural Rubber Re DOI: 10.13005/ojc/350119
• 1634 cm⁻¹ tillid 1,0

  “LLM confirmed rule peak-group candidate”

  Ashri 等 - 2018 - Modified Dioscorea hispida starch-based hydrogels DOI: 10.1016/j.ijbiomac.2017.10.125
• 1634 cm⁻¹ tillid 1,0

  “35 36 cm-1 The twin weak absorption bands at 1634 and 1613 are from C=C stretching vibration while the 37 cm-1 38 absorbances at 2847 and 2940 are attributed to the stretching vibration of aliphatic C-H groups.”

  Ataei 等 - 2020 - Electrosprayed PMMA microcapsules containing green DOI: 10.1088/1361-665X/ab9754
• 3275 cm⁻¹ tillid 1,0

  “The two prominent peaks at 3275.13 and 1635.54 are typical of N-H bond of amines and C=C stretch of alkenes or C=O stretch of amides [42] respectively.”

  Biomedical Applications of Cocoa Bean Extract-Mediated Silver Nanoparticles as Antimicrobial, Larvicidal and Anticoagulant Agents DOI: 10.1007/s10876-016-1055-2
• 1000 cm⁻¹ tillid 1,0

  “stretching), while the peaks within the range of 1000The pre-processing also significantly showed that the cm-1 could be seen through the absorption of alkenes 650 quantified FTIR spectra were distributed normally with functional group C-H”

  Aziz 等 - 2020 - FTIR and HPLC-Based Metabolomics of Yacon Leaves E DOI: 10.22146/ijc.43453
• 1628 cm⁻¹ tillid 1,0

  “A strong band at 1628 can also be assigned to the C=C stretch in the aromatic”

  Aziz 等 - 2017 - From Insulating PMMA Polymer to Conjugated Double DOI: 10.3390/polym9110626