Photodissociation of a ruthenium(II) arene complex and its subsequent interactions with biomolecules: A density functional theory study


The piano-stool RuIIarene complex [(η6-benz)Ru (bpm)(py)]2+ (benz0benzene, bpm02,2′-bipyrimidine, and py0pyridine), which is conventionally nonlabile (on a timescale and under conditions relevant for biological reactivity), can be activated by visible light to selectively photodissociate the monodentate ligand (py). In the present study, the aquation and binding of the photocontrolled ruthenium(II) arene complex [(η6-benz)Ru(bpm)(py)]2+ to various biomolecules are studied by density functional theory (DFT) and timedependent DFT (TDDFT). Potential energy curves (PECs) calculated for the Ru-N (py) bonds in [(η6-benz)Ru(bpm) (py)]2+ in the singlet and triplet state give useful insights into the photodissociation mechanism of py. The binding energies of the various biomolecules are calculated, which allows the order of binding affinities among the considered nuleic-acidor protein-binding sites to be discerned. The kinetics for the replacement of water in the aqua complex with biomolecules is also considered, and the results demonstrate that guanine is superior to other biomolecules in terms of coordinating with the RuII aqua adduct, which is in reasonable agreement with experimental observations. © Springer-Verlag 2012.

Publication Title

Journal of Molecular Modeling