catena-Poly[[μ3-hydroxido-tetra-μ2-pyridazine-1/2κ4N/N′;1/3κ2N/N′;2/3κ2N/N′-tetrakis(selenocyanato)-1κN,2κN,3κ2N-trizinc(II)]-μ-cyanido-1/2′κ2C/N]

In the crystal structure of the title compound, [Zn-3(NCSe)(4)(OH)(CN)(C4H4N2)(4)] (n) one of the two crystallographically independent zinc(II) cations is coordinated by two terminal N-bonded selenocyanato anions and two N atoms of two symmetry-related pyridazine ligands in a trigonal-bipyramidal geometry, while the other zinc(II) cation is coordinated by one terminal N-bonded selenocyanato anion, one mu-1,2-cyanido anion and three N atoms of three crystallographically independent pyridazine ligands in a slightly distorted octahedral coordination geometry. The zinc(II) atoms are further connected via a mu(3)-hydroxido anion into trinuclear building blocks. The formula unit consists of three zinc cations, four selenocyanato anions, one mu(3)-hydroxido anion, four pyridazine molecules as well as one cyanido anion. The asymmetric unit contains half of a formula unit. One of the zinc atoms, two selenocyanato anions, two pyridazine ligands and the mu(3)-hydroxido anion are located on a crystallographic mirror plane, whereas the cyanido anion is located on a twofold rotation axis. Therefore, this anion is disordered due to symmetry. The cyanido anions connect the metal centres into polymeric zigzag chains propagating along the a axis.