By controlling stoichiometry, three Copper(I) containing coordination polymers (2)(infinity)[Cu2Cl2(bpy)] (I), (2)(infinity)[Cu2Br2(bpy)] (II), and (3)(infinity)[CuBr(bpy)] (III) (bpy = 4.4'-bipyridine) have been synthesized in superheated water at 170 degrees C. The crystal structures of I and II are two-dimensional networks composed of Cu2X2 double chains bridged by 4.4'-bpy molecules through the nitrogen sites. The structure of III is a three-dimensional interpenetrating network constructed by concatenated 2D sheets. TGA studies indicate that these compounds are thermally stable up to 220 degrees C.