The preparations of multinuclear supramolecules assembled from 1,1¡¬-bis(terpyridyl)ferrocene, 1,1¡¬-bis(terpyridyl)biferrocene and 1,1¡¬-bis(terpyridyl)triferrocene (tpy-(fc)n-tpy, n =1-3) redox-active moieties with Ru2+ metal centers are described. The electrochemical measurements of the Ru2+ coordinated tpy-(fc)n-tpy complexes (1a (n=1); 1b (n=2); 1c (n=3)) are dominated by the Ru2+/Ru3+ redox couple (E1/2 from 1.35 to 1.38 V), Fe2+/Fe3+ redox couples (E1/2 from ∼0.4 to ∼1.0 V) and tpy/tpy-/tpy2- redox couples (E1/2 from 1.3 to 1.5 V). The appreciable variations detected in the Fe2+/Fe3+ oxidation potentials indicate that there is an interaction between the spacer and the Ru2+ metal centers. On the coordination of Ru2+ metal centers with tpy-(fc)n-tpy rises to a red-shifted and more intense 1[(d(£k)Fe)6] ¡÷ 1[d(£k)Fe)5(£k*tpyRu)1] transition in the visible region. The observed red-shifted absorption from 526 nm in monomeric [Ru(fctpy)2]2+ complex to ~560 nm in 1b and 1c reveals that there is a qualitative electronic coupling within the ferrocenyl array. The Fe-Fe interactions result in a red characteristic of the 1[(d(£k)Fe)6] ¡÷ 1[d(£k)Fe)5(£k*tpyRu)1] MMLCT transition.

The development of molecular wires where photoactive and electroactive terminals are linked by a large size molecular spacer may open new path in the field of storage and utilization of light energy. An important issue concerns how best to design the spacer that permit controlled transfer of electron along the molecular axis. Our design principle for a molecular wire has to fulfill following criteria : (i) an organometallic redox-active spacer to enhance the capability of transfer information along the molecular axis and (ii) modular synthetic approach to control length. The preparations of multinuclear supramolecular assembled from redox-active biferrocencyl spacer and ruthenium(II) terpyridine chromophore are described. Interestingly, substitution of a methoxy group on terminal terpyridine 4'-position of complex 13 will enhance the electronic coupling between the spacer and Ru2+ metal centers. The detailed properties about complex 13 are described in electrochemical results, UV-visible spectral data, and photo luminescent investigation.

none

none