title: catena-Poly[[[di-aqua-cobalt(II)]-bis-{μ-2-[3-(4-carboxyl-atophen-yl)pyridin-1-ium-1-yl]acetato}] dihydrate].
abstract: In the title polymeric coordination compound, {[Co(C14H10NO4)2(H2O)2]·2H2O} n , the Co(II) ion resides on an inversion center and exhibits a distorted o-cta-hedral coordination geometry defined by four O atoms from two pairs of equivalent monodentate carboxyl-ate groups from 2-[3-(4-carboxyl-atophen-yl)pyridin-1-ium-1-yl]acetate ligands and by two O atoms from two equivalent coordinating water mol-ecules. The zwitterionic di-carboxyl-ate ligands serve as bridges with two monodentate carboxyl-ate 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 inter-chain hydrogen bonding and π-π stacking inter-actions [inter-planar and centroid-centroid distances of 3.658 (3) Å and 3.653 (2) Å, respectively].
authors.affiliation: College of Chemistry and Materials Science, Huaibei Normal University, 100 Dongshan Road, Huaibei, Anhui 235000, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Gao
authors.forename: Xiu-Mei
authors.initials: XM
authors.lastname: Zhang