CODECS 2013 Workshop. San Lorenzo de El Escorial, Madrid, 18th –22nd April, 2013
UV-Vis Spectrum and Charge Transfer of a DNA Intercalated Ru(II)
Complex: A QM/MM Study
Chantzis Agisilaosa, Very Thibautb, Monari Antoniob and Assfeld Xavierb
a
CEISAM(UMR 6230), University of Nantes, 2 rue de la Houssinière BP92208 44322, Nantes,
France
b
SRSMC(UMR 7565), University of Lorraine, Boulevard des Aiguillettes BP70239, 54506,
Nancy, France
agisilaos.chantzis@univ-nantes.fr
The photophysical properties of Ru(II) complexes used as nucleic acid probes is still a
subject of great interest and intensive research. The so-called “light switch” effect1, observed for
some ruthenium complexes upon DNA intercalation is still not fully understood. Theoretical
investigations focusing on the elucidation of the structural and photophysical processes involved
upon intercalation are quite numerous and their findings can support the interpretation of
experimental data2,3.
The purpose of the present communication is to present a theoretical investigation of the
UV-Vis spectrum of a Ru(II) complex intercalated in a model double helix of B-DNA using Time
Dependent DFT (TD-DFT). The methodology followed involves the partition of the total system
into a QM (Ru complex) and a MM (B-DNA, water molecules, sodium ions) part and it has been
tested previously on a simpler system4. Besides this, we have also considered the possibility of
charge transfer from the base pairs of DNA to the complex by including the ones in the vicinity
of the complex to the QM part.
Fig. 1. The Ru(II) complex intercalated into the strand of DNA.
Acknowledgments. Financial funding from the ANR through the ANR-09-BLAN-0191-01
“PhotoBioMet” project is acknowledged.
References
1. A.E. Friedman, J.-C. Chambron, J.-P. Sauvage, N.J. Turro and J.K. Barton, J. Am. Chem. Soc., 112,
4960 (1990).
2. D. Ambrosek, P.-F. Loos, X. Assfeld and C. Daniel, J. Inorg. Biochem., 104, 893 (2010).
3. T. Very, S. Despax, P. Hébraud, A. Monari and X. Assfeld, Phys. Chem. Chem. Phys., 14, 12496
(2012).
4. A. Chantzis, T. Very, A. Monari, and X. Assfeld, J. Chem. Theor. Comput., 8, 1536 (2012).