Three new bridging ligands 2,2Ј-bis(1,2,4-triazin-3-yl)-4,4Ј-bipyridine (btb), 2,2Ј-bis(1,2,4-triazino[5,6-f]acenaphthylen-3-yl)-4,4Ј-bipyridine (btapb), 2,2Ј-bis(5,6-diphenyl-1,2,4-triazin-3-yl)-4,4Ј-bipyridine (bdptb) and their dimeric 2,2Ј-bipyr-(3) have been synthesized and characterized by elemental analysis, fast atom bombardment (FAB) mass spectrometry or electrospray mass spectrometry (ES-MS), 1 H NMR and UV/Visible spectroscopy. The binding behavior of these dimeric complexes with calf thymus DNA (CT-DNA) was investigated by electronic absorption spectroscopy, viscosity measurements, and equilibrium dialysis experiments. The hypochromism of the metal-ligand charge transfer (MLCT) band in the electronic absorption spectra of the dinuclear complexes 1, 2, and 3 is 8. 7%, 19% and 33%, respectively,