The crystal structure of the complex is determined by single crystal X-ray diffraction. <...> In the crystal, the cobalt(II) ion adopts a hexa-coordinate environment, and the structure units aggregate together to give birth to infinite 1D chains. <...> The 2D and 3D framework is constructed via intermolecular hydrogen bonds. <...> Keywords: 2,2-bipyridine-3,3-dicarboxylic acid (3,3-bpbc), cobalt(II) complex, crystal structure, coordination During the past decades, metal complexes containing hydrogen bonded water clusters have received a wide range of attention in the field of supramolecular chemistry and crystal engineering [ 1— 5 ]. <...> Due to its strength and directionality the hydrogen bond is perhaps the most important intermolecular interaction used in such endeavors. <...> In different chemical environments, the complexes with the same ion and ligand may form different structures [ 6, 7 ]. <...> Moreover, ligands containing aromatic rings and multicarboxylate have proved to be a powerful tool in the construction of multidimensional architectures [ 8 ] because they can be regarded as not only the hydrogen bond [ 9, 10 ] acceptors of carboxylate, but also the strong — stacking [ 11, 12 ] ability of aromatic rings. <...> In this paper, we successfully designed the 2,2-bipyridine-3,3-dicarboxylic acid (3,3-bpbc) ligand that consists of two carboxylate goups and aromatic ring systems, and its noncovalent linking sites lead to the aggregation of the neighboring complexes through hydrogen bonds and form a novel complex [Co(3,3-bpbc)(H2O)3]H2O. <...> In the unit cell, 3,3-bpbc binds to the cobalt atom in a chelate mode by two N atoms. <...> Elemental analyses (C, H, and N) were performed on a model Finnigan EA 1112 instrument. <...> IR spectra were recorded on a Nicolet IR_470 spectrophotometer using KBr pellets. <...> Several days later, pink transparent crystals formed by evaporating the solution at room temperature were collected and found suitable for X-ray diffraction. <...> The crystal structure of complex I was determined by X-ray singe crystal diffraction. <...> The crystal data and structure refinement are given in Table 1; selected bond distances (Е) and bond angles (deg.) are listed in Table 2. <...> The crystal unit structure of complex <...>