Photo-reactions of organometallic compounds are studied by NMR by illuminating the sample with a laser directly within the
superconducting magnet of the spectrometer. The photo-reactions of certain Ru(II) complexes with biological targets (guanosine
5'-monophosphate, tyrosine, tryptophan) give rise to Chemically Induced Dynamic Nuclear Polarization: CIDNP. The (photo)-CIDNP originates
from the hyperfine coupling within a pair of (photo-)chemically generated radicals which leads to a modification of the population
distribution of nuclear spin states. In the NMR spectrum, reaction products are observed with signals whose intensity can be
increased or decreased significantly compared to that observed at equilibrium (without illumination). Stationary CIDNP measures make
possible, in particular, to identify the sites of photo-reaction and to characterize the radicals formed with the atomic resolution
of NMR. They open up new perspectives for studying the photochemistry of Ru(II) or other transition metal complexes and for the
characterization of biological (macro)molecules. The work is carried out in collaboration with the teams of C. Moucheron - A. Kirsch
and N. Vaeck.
Web site: http://cop.ulb.ac.be