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Author: Subject: .1 M Water?
GreenD
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[*] posted on 23-4-2013 at 14:05
.1 M Water?


Bit confused.
Paper calls for a solution of reagents - (1eq and 1.2 eq - not that it matters) but then explains that this is in
"Water (.1M) and EtOH (.2M)"

? I've never seen anyone refer to the solvents, let alone water, in molarity.




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Pyro
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[*] posted on 23-4-2013 at 14:46


could they mean 1,8g of water? or water in EtOH where 1l of the mixture contains 1,8g H2O?



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Prometheus23
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[*] posted on 23-4-2013 at 19:38


It would be helpful if you could post some more details from the paper so we could see the full context.

But just taking a guess, could they have meant that the reagents being added were 0.1M in water and 0.2M in ethanol?
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GreenD
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[*] posted on 24-4-2013 at 19:57


Well the paper literally skims over this, as it is a "general procedure" and says
"Reagent A - 1eq and Reagent B - 1.2 eq were dissolved in water (.1M) and EtOH (.2M) and brought to reflux overnight."




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[*] posted on 25-4-2013 at 03:09


I interpret this as follows:

1. Weigh 1.0 equivalents of reagent A and dissolve in as much water as needed to make a 0.1M solution
2. Weigh 1.2 equivalents of reagent B and dissolve into ethanol to make a 0.2M solution
3. reflux overnight.

I agree it could be more clear.
Also, it doesn't say whether the reagents are mixed and refluxed together, but I guess that should be clear from the context.




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Prometheus23
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[*] posted on 25-4-2013 at 06:14


Yes exactly, that it what I meant phlogiston. They are giving the solvent and the concentration (essentially the volume of solvent to use) for each reactant.
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GreenD
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[*] posted on 6-5-2013 at 10:11


If only they would have thrown in "respectively"



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[*] posted on 6-5-2013 at 10:45


Did you end up trying out the procedure the way phlogiston and I interpreted? Or were we off base a little?
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[*] posted on 6-5-2013 at 12:15


I am trying it your method today. Previously I just decided to throw in a 1:2 eq h2o:etoh, and the reaction didn't work.

But going off your interpretation, I used about 10x fold more solvent.

Its odd because, by your interpretation, and if they had thrown in the word "respectively" after, they would be asking for
.1M 4-cyano-methanebenzenebromide in water
and
.2M Sodium Sulfite in ethanol...

Which doesn't make sense, solubility wise, so I switched the two... Everything goes into solution at high temps, but these are not soluble at low temperatures.

We'll see... they request it run over night at reflux.




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[*] posted on 6-5-2013 at 13:11


If you are still attempting to synthesize the compound you asked about in this thread:

http://www.sciencemadness.org/talk/viewthread.php?tid=22975#...

Then perhaps this procedure I came across could be of help to you.

http://www.organic-chemistry.org/abstracts/lit1/386.shtm

It essentially involves carrying out the reaction of your benzyl halide with excess sodium sulfinate in water under microwave irradiation (the latest fad it seems). I believe this could be carried out with sodium (bi)sulfite in place of a sulfinate to give the sulfonate you want.
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