Synthesis and Electrochemical Properties of Mixed‐metal Triangular Complexes Based on Ferrocene‐based Ligand and Dinuclear Arene Ruthenium Building Blocks

Ferrocene-based multidentate ligands have been widely used as metalloligands in crystal engineering because they self-assemble into mixed-metal complexes with various transition-metal salts. In the present study, the ferrocene-based ligand 1,2-di(4-pyridylthio)ferrocene (L-Fc) was complexed with dinuclear arene ruthenium building blocks [(p-cymene)(2)Ru-2(mu-L)](OTf)(2) to form the following trinuclear complexes with triangular structures: [(p-cymene)(2)Ru-2(mu-L)(mu-L-Fc)](OTf)(2) [L=5,8-dioxido-1,4-naphtoquinonato (1 a), 2,3-dichloro-5,8-dioxido-1,4-naphtoquinonato (1 b), 2,5-dioxido-1,4-benzoquinonato (2 a), 2,5-dichloro-3,6-dioxido-1,4-benzoquinonato (2 b), and oxalato (3): OTf=trifluoromethanesulfonate]. A similar complexation of the ferrocene-based ligand with [(p-cymene)(2)Ru2Cl4] afforded a V-shaped trinuclear complex [(p-cymene)(2)Ru2Cl4(mu-L-Fc)] (4). This study reveals the crystal structure and electronic states of 1-4. The absorption wavelengths and redox potentials of the trinuclear complexes depended on the type of L.