RTIL, 1.hex and anion substitution have long and its structural In this laborato
ID: 532160 • Letter: R
Question
RTIL, 1.hex and anion substitution have long and its structural In this laboratory experiment, you will synthesize a hexafluorophosphate, using a two-step process involving exchange. where n the number of carbons in the names. Therefore, they are often abbreviated as I mimlX, alkyl chain of the cation, "mim' stands for methylimidazolium and X the anion. N N-methylimidazole neat H20, rt 1-bromohexane a KBr Br Br PFe mim]Br KPF UNDERSTANDING THE ExPERIMENT In the first step of this reaction, N-methylimidazole and 1.bromobexane are mix "neat" meaning that no solvent is employed. With a substitution reaction occurs to yield [Co- heating, nucleophilic mimlBr which possesses a Group A anion and is water-soluble. In the second step of the reaction, water is mim Br and KPF. is added to convert mimlBr to PE added to dissolve ICs The byproduct of this step is KBr. Because IC mimlPF6 possesses a Group B anion, it is and significantly less soluble in water than is IC mim]Br, it can be isolated by extraction with dichloromethane followed by removal of dichloromethane by distillation. This two-step procedure is operationally simple and typically high yielding, but often RTILs prepared in this way are contaminated by halide salts, e.g., KBr. These salts may affect the physical properties of the RTIL and efforts must be made to remove the halide contaminant from the desired RTIL. INSTRUCTIONS A. SETTING UP THE ExPERIMENT 1. Pre-heat a heating mantle to 160-180°C by setting it to "10". Clamp a thermometer and reflux condenser to a retort stand above the heating mantle, leaving enough room for a 25 mL round bottom flask to fit between the condenser and the heating mantle. Connect the reflux condenser to a water supply using thin rubber tubing and the illustration to help you with your set up. Clamp the condenser to the retort stand. 2. Add 2-4 boiling chips to a clean and dry 25 mL boiling flask round bottom flask then, in the fume bood, 1.0 mL 1-methylimidazole CAUTION toxic by skin absorption corrosive; wear glovesl and 1.75 ml. of bromotexane CAUTION: ay be harmful ifExplanation / Answer
Identifiaction of the completion of the first step of the reaction:
due to the presence of Br- ions in the product, it would be slightly yellowish in colour.
As the product is an ionic liquid in the first step so change of nature of the liquid from less viscous to a more viscous state is observed.
The TLC (thin layer chromatography) of the reaction mixture can be done by taking three spots of namely the two starting materials and the reaction mixture. If no spot for starting material is visible in the TLC after running it, then the reaction has achieved completion.
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