Complexes of the type [Ru(N– N)2(tdzp)]Cl2, where N–N is 2,20 - bipyridine (bpy) (1), 1,10-phenathroline (phen) (2), dipyrido[3,2-d:20 ,3-f] quinoxaline (dpq) (3), which incorporate the [1,2,5]-thiadiazolo-[3,4-f ]- [1,10]- phenanthroline (tdzp) ligand, have been synthesized and characterized by IR, 1 HNMR, 13C-NMR, ESI-MS, elemental analysis, UV-Visible and luminescence spectroscopy. The molecular structure of complex 2 is confirmed by single crystal X-ray structure determination. A twodimensional cyclic water– chloride anionic {[(H2O)10(Cl)2] 2}n network has been structurally identified in a hydrophobic matrix of 2. Interaction of these complexes with Calf Thymus DNA (CT-DNA) was explored by electronic absorption and emission spectroscopy and circular dichroism spectroscopy.