Synthesis of ruthenium tris(2,2′-bipyridine)-type complexes tethered to peptides at 5,5′-positions

Utilization of 5′-amino-2,2′-bipyridine-5-carboxylic acid allows molecular design of ruthenium tris(bipyridine)-type complexes bearing two different functional groups. In this study, a novel ruthenium tris(bipyridine) derivative bearing viologen and tyrosine as an electron acceptor and donor, respectively, is synthesized. This synthesis exemplifies the effectiveness of the molecular design for functionalizing ruthenium bipyridine-type complexes. The photophysical properties are discussed in comparison with a reference ruthenium complex which has neither the electron acceptor nor donor.