A novel nickel(II) coordination polymer incorporating 1,4-phenylene-diacetic acid and 1,10-phenanthroline

The title nickel(II) coordination polymer, viz. poly[[bis(1,10-phenanthroline)tris(mu(3)-1,4-phenylenediacetato)trinickel(II)] dihydrate], {[Ni-3(C10H8O4)(3)(C12H8N2)(2)]center dot 2H(2)O}(n), consists of linear trinuclear building blocks with two crystallographically unique Ni atoms. One Ni-II atom and the geometric centre of one 1,4-phenylenediacetate ligand in the trinuclear unit both lie on inversion centres, while the other unique Ni-II atom lies near the inversion centre, together with another 1,4-phenylenediacetate ligand. Each pair of adjacent trinuclear units is bridged by 1,4-phenylenediacetate ligands, forming two kinds of infinite chains along the a and b axes, respectively. These two kinds of chains crosslink to yield a two-dimensional network in the ab plane. The two-dimensional sheets further stack along the c axis via pi-pi stacking interactions and hydrogen bonds, forming a three-dimensional supramolecular structure.