catena-Poly[[aqua­zinc(II)]-μ-N,N′-bis­(2-cyano-3-eth­oxy-3-oxoprop-1-en­yl)benzene-1,2-diaminido]

The slightly yellow-coloured title complex, [Zn(C18H16N4O4)(H2O)] n , crystallizes with one mol-ecule in the asymmetric unit. The structure clearly shows the mer-η(4) O,O,N,N-binding mode of the N,N'-bis-(2-cyano-ethyl-propeno-yl)-1,2-di-amido-benzene ligand stabilizing the Zn centre of a distorted octa-hedral environment. The fifth coordination site in one apical position is held by a coordinating solvent water mol-ecule whereas the complete octa-hedral coordination sphere is completed by coordination of one N atom from a CN group of a neighbouring mol-ecule, leading to the final polymeric structure consisting of zigzag staggered chains in parallel orientation along the c-axis direction. Between the coord-in-ated water solvent molecule and the N atoms of uncoord-in-ated cyano-groups of neighboured units, two H-bridge bonds are formed. One of these H-bridge bonds is of inter- whereas the other of intra-strand nature, leading to a two-dimensional network parallel to (110) stabilizing the supramolecular structure. Six Zn-O or Zn-N bonds are found with lengths ranging from 2.061 (1) to 2.185 (1) Å and bond angles about the Zn atom are clustered in the ranges 79.83 (4)-104.21 (4) and 167.05 (4)-170.28 (4)°.