Dicyanamide-bound mononuclear compounds Cp(dppe)FeN(CN)(2) (3) and Cp(PPh3)(2)RuN(CN)(2) (4) were isolated in high yields by the reactions of Cp(dppe)FeCl (1) and Cp(PPh3)(2)RuCl (2), respectively, with excess sodium dicyanamide. Compounds 3 and 4 are excellent precursors for the design of dicyanamide-bridged binuclear complexes [{Cp(dppe)Fe}(2)N(CN)(2)](SbF6) (5) and [{Cp(PPh3)(2)Ru}(2)N(CN)(2)](SbF6) (6) by the incorporation with 1 and 2, respectively. Controlling oxidation of 5 with ferrocenium hexafluorophosphate afforded the mixed-valence compound [{Cp(dppe)Fe}(2)N(CN)(2)](PF6)(2) (5a) which exhibits a broad absorption band in the near-infrared region (centered at 1500 nm, is an element of = 750 cm(-1) M-1) due to the intervalence charge transfer of Robin and Day class II mixed-valence system. Tricyanomethanide-bound mononuclear compounds Cp(dppe)FeC(CN)(3) (7) and Cp(Pph(3))(2)RuC(CN)(3) (8) were prepared by the same methods as 3 and 4 using potassium tricyanomethanide as the starting material instead. The tricyanomethanide-bridged binuclear complexes [{Cp(dppe)Fe}(2)C(CN)(3)](CF3SO3) (9) and [{Cp(PPh3)(2-)Ru}(2)C(CN)(3)](SbF6) (10) were prepared by the reactions between 7 and 1 and between 8 and 2, respectively. Cyclic voltammograms of the dicyanamide/tricyanomethanide-bridged binuclear complexes showed stepwise reversible one-electron oxidation waves with the potential separation of the two redox couples in the range 0.14-0.25 V, indicating the demonstrably electronic communication is operative between the organometallic components through a dicyanamide/tricyanomethanide spacer with metal(...)metal distances more than 7.8 Angstrom. Furthermore, the electronic coupling transmitted by the tricyanomethanide is appreciably greater than that by the dicyanamide. The complexes 3-10 were characterized by elemental analysis, IR, UV-vis, H-1 and P-31 NMR, and ES-MS. The crystal structures of 3 and 5-9 were determined by X-ray crystallography.