New bridging ligands, such as bpy-(COOCH2)-bpy (BL1), mbpy-(CH2)3COOCH2-bpy (BL2), bpy-COO(CH2)6OOC-bpy (BL3), and bpy-COOCH2PhPhCH2OOC-bpy (BL4), have been synthesized and coordinated to [RuL2(acetone)2](PF6)2 for various [Ru(L)2(BL)Ru(L)2](PF6)4-type dinuclear ruthenium complexes (where BL = BL1, BL2, BL3, BL4, and L = bpy, o-phen, DTDP). Their electrochemical redox potentials, spectroscopic properties and relative electrochemiluminescence were investigated in detail. All dinuclear Ru complexes exhibit MLCT (metal-to-ligand charge transfer) absorption and luminescence bands in the visible region. ECL intensities of dinuclear ruthenium(II) complexes were affected not only by the kind of the ligand, but also by the nature of the bridging ligand. Among the synthesized dinuclear Ru complexes, [(DTDP)2Ru(mbpy)-(CH2)3COOCH2-(bpy)Ru(DTDP)2](PF6)4 exhibited enhanced ECL intensities as high as 2.9 times greater than that of the reference, [Ru(o-phen)3](PF6)2.
Bibliographical noteFunding Information:
Financial supports from Kwangwoon University in the year 2007, Center for Bioactive Molecular Hybrids, and the RRC program of Ministry of Commerce, Industry and Energy are greatly acknowledged. J.M.L. acknowledges the support of the BK 21 program of the Ministry of Education.
All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry