Mixed-ligand binuclear Cu(II) complexes involving thiodiglycolate(2-) anion and nitrogen-donor ligands in the coordination sphere of composition [(phen)2Cu(mu-tdga)Cu(phen)](NO3)2 . 5H2O (1) and [(H2O)(pmdien)Cu(mu-tdga)Cu(pmdien)(H2O)](ClO4)2 (2), where PHEN=1,10-phenanthroline, H2tdga=thiodiglycolic acid, PMDIEN=N,N,N',N',N''-pentamethyldiethylenetriamine, have been prepared. Temperature dependence of magnetic susceptibility, EPR spectroscopy and single crystal X-ray analysis has been used to characterize these compounds. Magnetic susceptibility measurements over the 1.9-300 K temperature range revealed a weak antiferromagnetic interaction between two copper atoms with the exchange integral value 2J=-4.80 cm-1 for 1 and -0.71 cm-1 for 2. The bridging dianion of thiodiglycolic acid is coordinated in each of the two complexes in a different manner.