title: catena-Poly[diammonium [diaqua-bis(pyridine-2,4-dicarboxyl-ato-κN,O)cuprate(II)] [[diaqua-copper(II)]-μ-pyridine-2,4-dicarboxyl-ato-κN,O:O-[tetra-aqua-cadmium(II)]-μ-pyridine-2,4-dicarboxyl-ato-κO:N,O] hexa-hydrate].
abstract: The title mixed-metal complex, {(NH(4))(2)[Cu(C(7)H(3)NO(4))(2)(H(2)O)(2)][CdCu(C(7)H(3)NO(4))(2)(H(2)O)(6)]·6H(2)O}(n), contains one octa-hedrally coordinated Cd(II) center and two octa-hedrally coordinated Cu(II) centers, each lying on an inversion center. The two Cu(II) atoms are each coordinated by two O atoms and two N atoms from two 2,4-pydc (2,4-H(2)pydc = pyridine-2,4-dicarboxylic acid) ligands in the equatorial plane and two water mol-ecules at the axial sites, thus producing two crystallographically independent [Cu(2,4-pydc)(2)(H(2)O)(2)](2-) metalloligands. One metalloligand exists as a discrete anion and the other connects the Cd(H(2)O)(4) units, forming a neutral chain. O-H⋯O and N-H⋯O hydrogen bonds connects the polymeric chains, complex anions, ammonium cations and uncoordinated water mol-ecules into a three-dimensional supra-molecular network.
authors.forename: Guan-Hua
authors.initials: GH
authors.lastname: Wang
authors.forename: Zhi-Gang
authors.initials: ZG
authors.lastname: Li
authors.forename: Heng-Qing
authors.initials: HQ
authors.lastname: Jia
authors.forename: Ning-Hai
authors.initials: NH
authors.lastname: Hu
authors.forename: Jing-Wei
authors.initials: JW
authors.lastname: Xu