Synthesis and Optical Properties of Phenanthroline-Derived Schiff Base-Like Dinuclear RuII-NiII Complexes
Hannah Kurz, Charles Lochenie, Kristina G. Wagner, Sandra Schneider, Matthias Karg, Birgit Weber:
Chem. Eur. J., 24, 5100-5111 (2018)
Two phenanthroline-derived Schiff base-like ligands with a covalently-linked Ru(II) phosphorescent unit were synthesised and converted into bimetallic Ru(II)-Ni(II) complexes. The optical properties were studied to examine a possible photoluminescence quenching through a non-radiative energy transfer upon Coordination Induced Spin State Switch (CISSS) at the Ni(II) centre. Therefore the metalloligands and the Ni(II) complexes were studied by UV-Vis absorbance as well as steady-state and time-resolved emission spectroscopy in MeCN and pyridine solutions. It is demonstrated that the nature of the bridging ligand between the Ru(II) donor and the Ni(II) acceptor strongly influences the photophysical behaviour upon CISSS. For the complex with a phenazine bridge, photoluminescense quenching is observed in the presence of a paramagnetic Ni(II) centre.