Diaquabis(pyridine-2,5-dicarboxylato)cobalt(II)

A mononuclear cobalt(II) coordination complex, [Co(Hpydc)(2)(H2O)(2)] (pydc = 2,5-pyridinedicarboxylate, C7H4NO4), has been prepared from the hydrothermal reaction of Co(CH3COO)(2). 4H(2)O and H(2)pydc in water. Cobalt(II) is coordinated by four O atoms, two from pydc ligand, two from water molecules, and two N atoms from the pydc ligands, to form a slightly distorted octahedral geometry. The Co-O and Co-N distances range from 2.055 (2) to 2.169 (2) Angstrom. The discrete structure is further extended to form a three-dimensional structure involving weak hydrogen bonds.