title: Triaqua[2,2'-(propane-1,3-diyl)bis(5-carboxy-1H-imidazole-4-carboxylato-κ(2)N(3),O(4))]calcium(II) tetrahydrate.
abstract: In the title compound, [Ca(C(13)H(10)N(4)O(8))(H(2)O)(3)]·4H(2)O, the Ca(II) ion is hepta-coordinated by two N atoms and two O atoms from a tetra-dentate 1,3-bis-(1H-imidazole-4,5-dicarb-oxy-l-ate) propane dianion and three water O atoms, giving a distorted penta-gonal-bipyramidal coordination environment. The Ca-O bond lengths are in the range 2.354 (3)-2.453 (2) Å, while the Ca-N bond lengths are in the range 2.523 (2)-2.548 (2) Å. An intra-molecular O-H⋯O hydrogen bond between the carb-oxy and carboxyl-ate groups stabilizes the mol-ecular configuration. A three-dimensional network of N-H⋯O and O-H⋯O hydrogen bonds help to stabilize the crystal packing.
authors.affiliation: Department of Chemistry and Chemical Engineering, Henan University of Urban Construction, Pingdingshan, Henan, 467044,  People's Republic of China.
authors.forename: Ling-Zhi
authors.initials: LZ
authors.lastname: Du
authors.forename: Xia
authors.initials: X
authors.lastname: Li