Diruthenium Complexes of Axial Ferrocenyl−Polyynyl Ligands: The Cases of C<sub>6</sub>Fc and C<sub>8</sub>Fc

Four Ru<sub>2</sub>(Y-DMBA)<sub>4</sub>(C<sub>2<i>n</i></sub>Fc)<sub>2</sub> type compounds with <i>n</i> = 3, 4 and Y-DMBA = <i>N,N’</i>-dimethylbenzamidinate, <i>N,N’</i>-dimethyl-3-methoxybenzamidinate were prepared using a weak-base protocol and characterized using voltammetry and single-crystal X-ray diffraction. Structural studies yielded Fc−Fc (edge−edge) separations of 22.0 and 27.1 Å for <i>n</i> = 3, 4, respectively. The potential differences between two Fc oxidation couples were determined via voltammetric studies as 0.24 and 0.22 V for <i>n</i> = 3, 4, respectively, implying the retention of strong interferrocene electronic couplings over extended distances.