Poly[[bis[μ2-8-ethyl-5-oxo-2-(piperazin-1-yl)-5,8-dihydropyrido[2,3-d]pyrimidine-6-carboxylato]zinc(II)] dihydrate]

The title compound, {[Zn(C14H16N5O3)(2)]center dot 2H2O}(n) or [Zn(ppa)(2)]center dot 2H(2)O}(n), where ppa = 8-ethyl-5,8-dihydro-5-oxo-2-(1-piperazinyl)-pyrido(2,3-d)-pyrimidine-6-carboxylate, was synthesized under hydrothermal conditions. The Zn-II atom (site symmetry (1) over bar) exhibits a distorted trans-ZnN2O4 octahedral geometry defined by two monodentate N-bonded and two bidentate O,O-bonded ppa monoanions. The extended two-dimensional structure arising from this connectivity is a square grid and the disordered uncoordinated water molecules occupy cavities within the grid. An N-H center dot center dot center dot O hydrogen bond occurs.