Four new 2,2′-bipyridine and 1,10-phenanthroline complexes, namely [Mn(phenca)2]·(H2O)2 (1), [Cu4(phen)4(OH-)4(H2O)2](DMF)4(ClO4-)4(H2O) (2), [Cu2(2,2-bipy)2(C2O42-)(H2O)2(NO3)2] (3) and [Cu(2,2-bipy)2(ClO4-)](ClO4-) (4) (2,2′-bpy = 2,2′- bipyridine, Hphenca = 1,10-phenanthroline-2-carboxylic acid) have been synthesized by a hydrothermal reaction. The products were characterized by elemental analysis, infrared spectroscopy and X-ray crystal diffraction. While strong hydrogen bonds play central roles in the formation of the 3D structure, the combined influence of the weak interactions such as π⋯π interactions is also evident in the structures. A preliminary investigation on the ion exchange properties of the complexes is presented. [ABSTRACT FROM AUTHOR]