A novel π-conjugated Ru(II) dinuclear complex containing a new azobenzene-bridged bis(terpyridine) ligand was synthesized and its photochemical and electrochemical properties were investigated. The ligand underwent reversibletrans-cisphotoisomerization, whereas the Ru complex did not show such photoisomerization behavior. Cyclic voltammetry of the complex displayed a reversible one-step 2e−oxidation wave due to Ru(III)Ru(III)/Ru(II)Ru(II) and four le−reduction waves indicating the formation of mixed-valence states when the electrons are accumulated at the ligand-based orbitals.