Diruthenium Complexes of Axial Ferrocenyl-Polyynyl Ligands: The Cases of C6Fc and C8Fc

Four Ru-2(Y-DMBA)(4)(C(2n)Fc)(2) type compounds with n = 3, 4 and Y-DMBA = N,N'-dimethylbenzamidinate, N,N'-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 angstrom for n = 3, 4, respectively. The potential differences between two Fc oxidation couples were determined via voltammetric studies as 0.24 and 0.22 V for n = 3, 4, respectively, implying the retention of strong interferrocene electronic couplings over extended distances.