Saturday, 18 July 2009

Excited state intramolecular proton transfer

Actually there is a second article with my name on it that just came out. So I'll use the chance to advertise for it a little bit as well. It is a review (at the time of submission also partially a preview) of excited state intramolecular proton transfer cases. The context is that it is part of a special birthday issue. In fact it is kind of interesting how professors have symposia instead of birthday parties and give each other journal issues for presents ... but that is a different question.

This figure, which is similar to the graphical abstract, kind of shows what's going on: You have a molecule with an intramolecular hydrogen bond (the red atom is typically oxygen, the green one oxygen or nitrogen). You excite with a high frequency UV-photon. Then in an ultrafast transfer process with no or almost no barrier the proton moves to the other side. The new tautomer may either emit a photon with strongly Stokes shifted fluorescence (as for example bipyridyl-diol from the last post) or it may exhibit internal conversion (as e.g. 2-(2'-hydroxyphenyl)-benzothiazole in gas phase).

6 comments:

Jeongeun said...

Can I ask you what program do you use to draw the molecules? Your picture is so sweet !!

Felix said...

thanks :)
it is pymol for the molecules and microsoft publisher for the lines and "photons"

Anonymous said...

may I ask what is the prospect of studying these systems, what is interesting, what questions can be answered? Or is only a promising practical application???

Felix said...

from a basic point of view these systems are studied to answer questions about proton transfer as you have it in acid base reaction or proton exchange in water

the advantage is that you can trigger this systems with a pump pulse and therefore you have different ways of studying compared to ground state equilibria

applications are: sunscreens, laser dyes, photostabilizers, ...

Anonymous said...

Dear Felix

I am, working on derivatives of 2 - (H-imidazo [1,2-a] pyridin-2-yl) phenol. Almost all of my compound have sufficiently strongly expressed fluorescence due ESIPT. And you have some experience in working with these compounds. I would like you to consult if you do not mind about the methods of calculation of such systems.
If you will be conveniently would like to ask you some questions in letter or any other convenient way.
Thanks in advance

Felix said...

hi, aside from the paper mentioned in this post, you could check:
http://pubs.acs.org/doi/abs/10.1021/jp050288k
or
http://dx.doi.org/10.1021/jp9032172
(http://chemical-quantum-images.blogspot.com/2009/07/bipyridyldiol.html)

and feel free if you want to write me an email:
felix.plasser "at" univie.ac.at