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Offline zeshkani

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quick questions
« on: October 09, 2007, 10:32:33 PM »
just a quick question how is it possible to recrystallize under inert gas

and also since a mixture of enantiomers is 50:50 is it possbile to increase one more then the other enantiomer ??

thanks

Offline Borek

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Re: quick questions
« Reply #1 on: October 10, 2007, 03:28:32 AM »
just a quick question how is it possible to recrystallize under inert gas

Are you asking for experimental setup?

Quote
and also since a mixture of enantiomers is 50:50 is it possbile to increase one more then the other enantiomer

What do you mean by "increase one more then the other"?
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Offline AWK

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Re: quick questions
« Reply #2 on: October 10, 2007, 04:40:08 AM »
j
and also since a mixture of enantiomers is 50:50 is it possbile to increase one more then the other enantiomer ??

thanks
There are special procedures for resolving of racemates, but they depend on types of compounds. Only in a few cases it is possible to obtain a pure enantiomer from racemate by seeding with crystals of needed enantioner
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Offline zeshkani

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Re: quick questions
« Reply #3 on: October 10, 2007, 11:28:06 PM »
Are you asking for experimental setup?

yes how can it be done experimentally, and what would be the setup, i have all the glassware and stuff like that

What do you mean by "increase one more then the other"?
this is the question: "how could you increase the yield of one enantiomer of a six-coordinate tris(chelate) metal complex, beyond the theoretical yiled of 50%"

Offline hmx9123

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Re: quick questions
« Reply #4 on: October 11, 2007, 09:15:09 PM »
Sparge the solvents you're using with inert gas.  Evacuate a hot schlenk tube and let cool to room temperature.  Against a backflow of inert gas, add your material.  Canula over your sparged solvent.  Stopper the flask under argon flow, then seal.  Stick in the freezer.  Let crystals grow.

As for your question of increasing yield of one enantiomer, that doesn't have to do with recrystallization, but rather the reaction conditions themselves.

Offline Electro

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Re: quick questions
« Reply #5 on: October 11, 2007, 09:42:47 PM »
Quote
Couldn't you also separate a racemic mixture via HPLC?

Yes, but it can be done with chiral phases
« Last Edit: October 12, 2007, 01:11:13 AM by AWK »

Offline alkufi

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Re: quick questions
« Reply #6 on: February 11, 2008, 08:31:19 AM »
thanks for this ask but u need to go to www.wikipedia.org website for more information

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