Book of Abstracts - Ruhr-Universität Bochum

P-61
ISBOMC `10 5.7 – 9.7. 2010 Ruhr-Universität Bochum
Fluorescent Rhenium(I)tricarbonyl Complexes Based on a Novel
Bisphenanthridinyl Chelate
Lukasz Raszeja, a and Nils Metzler-Nolte *a
a Ruhr-University Bochum, Faculty of Chemistry and Biochemistry, Department of
Inorganic Chemistry I, Universitätsstr. 150, 44801 Bochum, Germany
E-mail: LukaszRaszeja@aol.com
Fluorescence microscopy is a powerful technique for the imaging of biological systems. Beside
making endogenous cell organelles visible by specific staining methods, it is also possible to monitor
the intracellular distribution of fluorescently labelled compounds such as peptides, oligonucleotides or
drugs in general. Right now most of the fluorescent dyes used for labelling are organic compounds
based on an aromatic heterocycle like in the case of fluorescein, acridine or cyanine. By now, the
number of applications of d 6 metal complexes for cellular imaging experiments is modest. Published
systems use the typical luminescent Ir(III), Ru(II) and Re(I) metal complexes. 1
We have developed a novel chelating ligand system based on phenanthridine. This ligand is
fluorescent itself, but by complexing a fac-Rhenium(I)tricarbonyl core the molecule exhibits an
enhanced absorption and a stronger and red shifted fluorescence. With a typical broad absorption
maximum between 310 nm and 380 nm the complex shows strong emission at 540 nm by excitation at
350 nm. The large Stokes shift is a big advantage in comparison to the typical organic dyes due to
prevent self-quenching processes. Beside the application in fluorescence microscopy our ligand could
act as a potential radio marker in the case of complexing the isostructural { 99m Tc(CO)3} core.
Several compounds based on the Bisphenanthridine moiety were synthesized (example in Fig. 1), fully
characterized and finally used for cellular imaging and uptake experiments (Fig. 2). The synthesis of
bioconjugates of peptides and PNA was also successful and cellular uptake studies show interesting
and promising results.
References
O
O
N
N
N
I
Re
CO
CO
CO
Br
Fig. 1 Structure of the fluorescent Re I complex 1. Fig. 2 Fluorescence image of IMIM-PC2 cells after
incubation with 1 (5 µM, 24 h).
1. V. Fernández-Moreira, F. L. Thorp-Greenwood, M. P. Coogan, Chem. Commun. 2010, 46, 186-202.
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