title: A new polymorph of catena-poly[[tri-aqua-cadmium(II)]-μ(2)-pyrazine-2,3-dicarboxyl-ato].
abstract: The title complex, [Cd(C(6)H(2)N(2)O(4))(H(2)O)(3)](n), is a new monoclinic polymorph. The ortho-rhom-bic form has previously been reported [Ma et al. (2006 ▶). Acta Cryst. E62, m2528-m2529]. The Cd-N and Cd-O bond lengths range from 2.265 (3) to 2.333 (3) Å; a weak Cd-O inter-action is also present, the inter-atomic distance being 2.658 (4) Å. The Cd(II) ions, which have a distorted penta-gonal-bipyramidal geometry, are bridged by pyrazine-2,3-dicarboxyl-ato ligands, forming a zigzag chain structure. The chains are connected by O-H⋯O hydrogen bonds into a three-dimensional framework.
authors.affiliation: Instrumental Measurement and Analysis Center, Fuzhou University, Fuzhou, Fujian 350002, People's Republic of China.
authors.forename: Hua
authors.initials: H
authors.lastname: Yin