Novel ruthenium−acetylide dendrimers were synthesized by using tris(4-ethynylphenyl)amine as the bridging ligand up to the second generation by a convergent method. Multistep reversible redox behavior in the cyclic voltammogram and a bathochromic shift with an increase in the number of ruthenium species except for the second-generation dendrimer in the UV–vis spectra suggested an intramolecular interaction among ruthenium species.

Novel trinuclear ruthenium complexes have been prepared by using tri(4-ethynylphenyl)amine as a bridging ligand. Cyclic voltammetry of the trinuclear ruthenium complexes revealed stepwise quasi-reversible redox behavior of three ruthenium–acetylide species and the central triphenylamine unit, whereas the mononuclear analog showed two sequential quasi-reversible redox waves. The spectroelectrochemical UV-VIS spectral studies suggested that the 1e− oxidized triruthenium species was stable and showed a characteristic absorption at λmax = 505 nm. Chemical oxidation of the triruthenium complex with ferrocenium hexafluorophosphate led to the isolation of the 1e− oxidized complex, the near-IR spectrum of which revealed an intervalence charge transfer band due to the electronic coupling among three ruthenium species. The 1e− oxidized triruthenium complexes can be classified as class II mixed-valence compounds.