The ligands 4'-(4-(methylthio)phenyl)-2,2':6',2"-terpyridine (L-1), 4'-((4-(methylthio)phenyl)ethynyl)- 2,2':6',2"-terpyridine (L2), and bis(tridentate) bridging ligand 2,3,5,6-tetra(pyridine-2-yl)pyrazine (tpp) were used to prepare the complexes [Ru(L-1)(2)][PF6](2) ([1][PF6](2), [Ru(L-2)(2)][PF6](2) ([2][PF6](2)), [{(L-1)Ru}(mu-tpp){Ru(L-1)}][PF6](4) ([3][PF6](4)), and [{(L-2)Ru}(mu-tpp){Ru(L-2)}][PF6]4 ([4][PF6]4). Crystallographically determined structures give (SS)-S-... distances of up to 32.0 angstrom in [4](4+).On the basis of electrochemical estimates, the highest occupied molecular orbitals of these complexes fall between -5.55 and -5.85 eV, close to the work function of clean gold (5.15.3 eV). The decay of conductance with molecular length across this series of molecules is approximately exponential, giving rise to a decay constant (pseudo beta-value) of 1.5 nm(-1), falling between decay factors for oligoynes and oligophenylenes. The results are consistent with a tunnelling mechanism for the single-molecule conductance behavior.