Poly[[(μ-aqua)[μ(4)-4-(carboxyl-atometh-yl)ben-zo-ato]cobalt(II)] hemi[1,4-bis-(pyridin-4-ylmeth-yl)piper-azine] hemihydrate].

In the title com-pound, {[Co(C(9)H(6)O(4))(H(2)O)]·0.5C(16)H(20)N(4)·0.5H(2)O}(n), two-di-men-sional coordination polymer slabs are held together in the three-dimensional crystal structure by means of O-H⋯N hydrogen bonding between bound water mol-ecules and pyridyl N atoms of cocrystallized 1,4-bis-(pyridin-4-yl-meth-yl)piperazine mol-ecules.