catena-Poly[[[di­aqua­cobalt(II)]-bis­{μ-2-[3-(4-carboxyl­atophen­yl)pyridin-1-ium-1-yl]acetato}] dihydrate]

In the title polymeric coordination compound, {[Co(C(14)H(10)NO(4))(2)(H(2)O)(2)]·2H(2)O}(n), the Co(II) ion resides on an inversion center and exhibits a distorted o­cta­hedral coordination geometry defined by four O atoms from two pairs of equivalent monodentate carboxyl­ate groups from 2-[3-(4-carboxyl­atophen­yl)pyridin-1-ium-1-yl]acetate ligands and by two O atoms from two equivalent coordinating water mol­ecules. The zwitterionic di­carboxyl­ate ligands serve as bridges with two monodentate carboxyl­ate and the metal ions are linked by double bridges, forming polymeric chains running along [01-1]. The chains are further stabilized and associated into layers parallel to (011) through intra- and inter­chain hydrogen bonding and π–π stacking inter­actions [inter­planar and centroid–centroid distances of 3.658 (3) Å and 3.653 (2) Å, respectively].