To explore the potential of [Co(phen)(2)CO3](+) as anion receptor, the complex salt [Co(phen)(2)CO3](4-aminobenzenesulphonate)(center dot)6H(2)O was synthesized and characterized by X-ray crystallography, elemental analyses, spectroscopic studies (IR, UV/Visible, H-1, C-13 and Co-59 NMR), solubility product and conductance measurements. The complex salt crystallizes in the triclinic space group P (1) over bar with unit cell constants: a = 10.803(2), b = 11.758(2), c = 15.190(3) angstrom, alpha = 99.66(3)degrees, beta = 103.53(3)degrees, gamma = 113.54(3)degrees. X-ray structure determination revealed the presence of one [Co(phen)(2)CO3](+), one 4-aminobenzenesulphonate ion and six lattice water molecules per asymmetric unit. Two 1,10-phenanthroline and one carbonato ligands (each bidentate) showed distorted octahedral geometry around the central Co(III) metal ion. Supramolecular hydrogen bonding networks formed by C-H center dot center dot center dot O, O-H center dot center dot center dot O and N-H center dot center dot center dot O interactions besides electrostatic forces of attraction stabilize crystal lattice. The structural studies suggest that [Co(phen)(2)CO3](+) is a potential anion receptor for the 4-aminobenzenesulphonate ion in aqueous medium. (C) 2009 Elsevier B.V. All rights reserved.