My longest project so far

Just today we were told that a paper of us has appeared online:
Chem. Eur. J. 2012, 18, 12372-12387
(UPDATE: it has been published with page numbers at 24-9-2012)

It is a collaboration with the groups of Prof. Wijmenga (Nijmegen, NL), Prof. Bickelhaupt (Amsterdam, NL), Sychrovsky (Prague, CZ) and Prof. Sponer (Brno, CZ), which started in 2006 when I was still in Amsterdam in the group of Matthias Bickelhaupt.

A few years before we had published a Communication in the Journal of the American Chemical Society:
J. Am. Chem. Soc. 2004, 126, 16718-16719
that dealt with the calculation of NMR chemical shifts of DNA base pairs. As a result, Sybren Wijmenga contacted us if we could do something for the calculation of NMR chemical shifts as a function of the glycosidic torsion angle. This angle determines how the DNA base rotates over the sugar moiety, as shown in the following figure:

Rotation of the DNA base over the sugar moiety

This rotation has a profound effect on the NMR chemical shifts, as shown in the paper, but exactly how was not clear from experiments. Moreover, there were NMR signals that were not clearly understood, and theory might help here. It took some time to get all correctly (in fact, approximately six years!!), but it was worth the wait. Have a look...