Hydrothermal reaction of CoCl2̇ 6H2O, H 6chhc (all-cis-1,2,3,4,5,6-cyclohexanehexacarboxylic acid), phen (1,10-phenanthroline), and NaOH in aqueous solution afforded a new coordination polymer Co(phen)(H2O)(H2chhc)1/2, which crystallizes in the space group P1- with the cell constants a = 7.267(2), b = 10.749(2), c = 10.826(2) Å ,α = 97.86(3), β = 103.62(3), γ = 95.00(3)°,V = 807.8(3) Å3 and Z = 2. The [Co(phen)(H2O)]2+ cations in the title complex are interlinked by the di-protonated (H2chhc)4? anions in a η6μ4 bridging mode to form ∞ 1[Co(phen)(H2O)(H2chhc)1/2] polymer chains running along the [100] direction. Variable temperature magnetic susceptibility studies revealed the presence of weak, long-range antiferromagnetic ordering and zero-field splitting [J = ?0.32(5) cm ?1 and D = 11.5(1) cm?1 with g = 2.306(4)]. The IR spectrum and results of thermal and elemental analyses are also presented. © 2011 Verlag der Zeitschrift für Naturforschung, Tübingen.