Sciencemadness Discussion Board

Ethylenediamine with a red tint

dangerous amateur - 14-7-2012 at 10:06

I just got some ethylenediamine, wich is hard to get here.

Thing is, this stuff seems to be rather old.

It is not colorless, it has a slight reddish tint.
I do not have experience with this stuff yet, but it is supposed to look like clear water.
It smokes white when it has air contact like it should and it smells like it should.

Do you think it's still OK to use?
How does outdated ethylenediamine look like?

[Edited on 14-7-2012 by dangerous amateur]

Mailinmypocket - 14-7-2012 at 11:56

Dont really know what could be causing the red color, mine is a fairly old bottle and the color is a very light amber... sort of looks like watered down beer. Its supposed to be colorless though... Either way it has always worked just fine.

Try making some transition metal complexes with it to see if it performs reasonably!

kristofvagyok - 14-7-2012 at 14:10

Quote: Originally posted by dangerous amateur  
I just got some ethylenediamine, wich is hard to get here.

Thing is, this stuff seems to be rather old.

Do you think it's still OK to use?
How does outdated ethylenediamine look like?
[Edited on 14-7-2012 by dangerous amateur]

Fresh and clear ethylenediamine looks like water, it is smelly as ***** and if it's not like this, it is recommended to distill it from anhydrous KOH.

And it should be stored under argon in a sealed ampoule.

ScienceSquirrel - 15-7-2012 at 04:07

I would not worry about it.
A little coloured material goes a long way.

dangerous amateur - 15-7-2012 at 12:08

Thanks for your opinions guys.
It's really just a slight tint, watered down beer is a pretty good description.

Quote:

Try making some transition metal complexes with it to see if it performs reasonably!

Can you suggest a certein synthesis that gives a significant result?

Dr.Bob - 15-7-2012 at 12:48

Most amines turn dark over time due to N-oxides, amine carbonate salts, and other decomp. products. It is difficult to tell the extent of purity without some analytical method or device, but often the color is due to a small impurity. I would not purify something I don't need immediately, as it will only go bad again, unless you can keep it cold, and under argon or nitrogen.

Mailinmypocket - 16-7-2012 at 04:28

Quote:

Try making some transition metal complexes with it to see if it performs reasonably!

Can you suggest a certein synthesis that gives a significant result?[/rquote]

Sure - give this a try: http://infohost.nmt.edu/~jaltig/CobaltComplex.pdf

It yields a nice crop of glistening, forest green crystals :)

You can also try making a similar salt with nickel instead of cobalt