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.