| Molecular electronics is one of the most attractive and actively areas of chemistry in recent years. As an important part of molecular devices, molecular wires play a significant role in the development of molecular electronics. Complexes in which two redox-active transition-metal moieties are linked together by an unsaturated conjugated bridging ligand have received great interest, first as a testing ground for all aspects related to intramolecular electron transfer and then as models for and principal constituents of possibly conducting molecule-based "wires".Synthesis and properties of ruthenium complexes linked byη2 -S2C, Py, PPh3 and PMe3 as the ligands were systematically carried out. The work is more specifically described below.1. Three kinds of conjugated bridging bimetallic were synthesized. The structures for all these new compounds were fully characterized by elemental analysis, 1HNMR, 13CNMR, 31PNMR, UV-vis spectroscopies.2. Spectral and electrochemical properties of RuCl(CO)(PPh3)2(η2-S2CCH=CH-Ar--CH=CHCS2)RuCl(CO)(PPh-3)2 (Ar=-C6H4-, -C12H8-, -C6H4-N=N-C6H4-) in CH2Cl2 have been investigated by UV-vis, cyclic voltammetry and square wave voltammetry. In electrochemical studies, this kind of molecular wires are almost insulating, and there is no interaction between the two ruthenium groups. This unusual result can be attributed to the strong electron-withdrawing effect ofη2-S2C group interrupting intramolecular electron transfer.3. Spectral and electrochemical properties of [RuCl(CO)(Py)(PPh3)2]2(μ-CH=CH--Ar-CH=CH) and [RuCl(CO)(PMe3)3]2(μ-CH=CH-Ar-CH=CH) (Ar=-C6H4-,-C12H8-, -C6H4-N=N-C6H4-,-C6H4-CH=N-C6H4-,-C6H4-CH=CH-C6H4-,-C6H4-C≡C-C6H4-) in CH2Cl2 have been investigated by UV-vis, cyclic voltammetry and square wave voltammetry. The result of the experiment indicates that [RuCl(CO)(Py)(PPh3)2]2 (μ-CH=CH-Ph-CH=CH) and [RuCl(CO)(PMe3)3]2 (μ-CH=CH-Ph-CH=CH) have strong ability in electron transfer. The first oxidative potential of the complexes containing Py and PPh3 ligands are more negative than those PMe3 specials, and is contributed to the strong electron donation effect of Py ligand.
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