Saturday, December 08, 2007

Colourful Chemistry

I'm doing lots of new chemistry in my new job which is great. Since I started my career as an organic chemist more or less everything has been supposed to be colourless or white.
What makes the chemistry I'm doing now even greater is that it has colour whilst still being organic chemistry.
Here's some recent pretty pictures. Check out my beautiful green reaction.
And how about this product from another reaction? Initially I assumed that the product was impure but what do you know it's supposed to like like this.
In your face inorganic chemists! Can anyone guess what I made? It is a classic reaction taught in first year university organic chemistry. It's nice to see the chemistry I have been teaching undergraduates is useful and actually works in the lab. D!

12 comments:

Kai said...

very pretty!

The bottom picture looks like an azobenzene compound. I did my diploma work on azobenzene stuff and my PhD on azos/stilbenes/tolanes, with colors from yellow to deep purplish red. Fun when flashing!

Daniel Sejer said...

Close but no cigar! I agree about columning this stuff. It's pretty easy to see when the column is done and which fractions to combine. And you can check your TLC just by looking at it straight out of the TLC jar. D!

Kai said...

what about stilbene? I figured after posting that an azo probably wouldn't have surprised you with the color...

or what about one of those guys with a C=N in between the two aromatic rings? I know they are colored, but haven't worked with them.

I actually thought your first picture could be a Vilsmeyer reaction, which would make sense for stilbenes and the others.

I made stilbenes by Wittig, Wittig-Horner, or a Knoevenagel-type reaction which actually is the best and easiest thing around for making nitrostilbenes. Uses nitrophenylacetic acid.

Ψ*Ψ said...

Nice to see someone else making something bright and pretty! Colorful chemistry is much more fun than white-to-pale-yellow-or-beige, and IME it's easier too (at least for chromatographic purposes). On any given day in my lab, you can rummage through a few drawers and drag out something for pretty much every color of the spectrum. :)

Daniel Sejer said...

I wasn't surprising that my compound was bright orange I just wasn't ready for it. You are getting very close Kai. What I did was to nitrate a substituted phenol using HNO3 in CH2Cl2. Another great afvantage about this colourful chemistry is that you can't see your impurities by looking at the compound. It all looks the same. On the picture the big flask in the centre contains the clean material and the two small flasks are impure samples. D!

Anonymous said...

looks like a 2,4-dinitrophenylhydrazone derivative

Greg the Chemist said...

Looks like a good old fashioned 2,4-DNP hydrazone derivative to me.

Daniel Sejer said...

It's not a hydrazone but a ortho-nitrated phenol. The green reaction is an alkylation of a substituted phenol. D!

Kai said...

so is the green color from copper or just unpredictable friedel-crafts color (usually black in my experience...)?

And was the para position blocked on your phenol? How else would you get the ortho isomer?

Daniel Sejer said...

The green reaction is an alkylation of a phenol.
The starting material for making the orange product only had the ortho- and meta-positions (relative to the phenol) unsubstituted. D!

Henrik T. Simonsen said...

Dearest Daniel
If you like colours, then I can only recommend that you return to Natural Product Chemistry. Since I started working in this field, I have been working with colours from pale yellow to deep deep purple/blue colours. And then it gets really funny, when you can show the molecular biologist colours changes just by adding water (you dont have to tell them about the change in ion-strength and pH)
Liniar tri-pyrrole compounds are great fun in the lab, since the molar absorpbicity (epsilon) get up to about 150.000. Many dies are around 10.000 to 20.000. Though they are very toxic they look great. But that the way life is.
Anthocyanins are another group of colourfull and loverly compounds, and not so toxic.

Liquidcarbon said...

I've got something to share, too :)
http://liquidcarbon.livejournal.com/22793.html