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 1 
 on: Today at 05:02:25 PM 
Started by smghz - Last post by smghz
So twice in a row I was attempting to do solid-state peptide synthesis. When trying to couple just the first two amino acids, I performed the Kaiser test to ensure that the amines are protected by Fmoc. But while the beads were colorless, the solution turned deep blackish-blue-purple like color.

What are common reasons attributed for such failures? I fear that I might redo the entire experiment again, but I'd like to know what are the mishaps that can block (virtually) complete coupling. thanks.

 2 
 on: Today at 04:48:56 PM 
Started by vikram - Last post by vikram
I have no idea what the ppm difference will be, considering I have no idea what the molecule is, and such things are tough to predict anyways. I just know that high field NMRs will resolve peaks better, so small shifts in crowded areas can be observed more clearly.

No not like that. By your answer I thought that there is a certain chemical shift above which we can observe anion-π interaction more commonly. Is it so?

 3 
 on: Today at 03:42:48 PM 
Started by smghz - Last post by smghz
So helpful, thanks!

 4 
 on: Today at 10:02:15 AM 
Started by vikram - Last post by wildfyr
I have no idea what the ppm difference will be, considering I have no idea what the molecule is, and such things are tough to predict anyways. I just know that high field NMRs will resolve peaks better, so small shifts in crowded areas can be observed more clearly.

 5 
 on: Today at 09:59:41 AM 
Started by Ch-Eng - Last post by wildfyr
Well, wikipedia has the mechanism right in the "ozonolysis" article. https://en.wikipedia.org/wiki/Ozonolysis#Reaction_mechanism. All your compounds are pretty much multi-alkenes, and ozonolysis will occur indiscriminately at each one. If you aren't able to follow the mechanism in that article, then there is quite a bit of organic chemistry which we can't really teach you over the internet. Perhaps this Khan academy video will help https://www.youtube.com/watch?v=bFj3HpdC4Uk

 6 
 on: Today at 09:22:35 AM 
Started by rsideguy16 - Last post by rsideguy16
Hey everyone! I'm new here (hopefully this is the right place to ask!  :-[) and I just had a question regarding a problematic chemical reaction. One of my homework questions wants me to show the product and reaction mechanism of

CC(C)[O-].CC(C)[O-].CC(C)[O-].[Al+3] + CCC(C)[O-].CCC(C)[O-].CCC(C)[O-].[Al+3] + CCO  :rarrow: ?

That is Aluminum Isopropoxide + Aluminum-tri-sec-butoxide + Ethanol  :rarrow: ?

One of my classmates said that one of the products is Aluminum Oxide [Al+3].[Al+3].[O-2].[O-2].[O-2] but I have no idea how she got that. A thorough explanation would be super helpful! Thank you in advance!  :)

 7 
 on: Today at 07:22:22 AM 
Started by kevin18016 - Last post by kevin18016
Thank you very much!  No, I don't have access to those things. I'm a sophmore and don't get the good stuff till a little further down the line.

 8 
 on: Today at 05:26:34 AM 
Started by cidmodule - Last post by Borek
Please don't cross post. Locked here.

 9 
 on: Today at 05:12:50 AM 
Started by BTE-Dan - Last post by Enthalpy
Wiki.

 10 
 on: Today at 05:10:17 AM 
Started by smghz - Last post by Enthalpy
Do you believe these two representations differ? (Apart from the ionization)

Molecules can differ by the relative positions of sub-groups, but in such flat representations, this information is missing.

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