catena-Poly[[[(1-ethyl-6-fluoro-4-oxo-7-(piperazin-1-yl)-1,4-dihydro-quinoline-3-carboxyl-ato-κO,O)copper(II)]-μ-1-ethyl-6-fluoro-4-oxo-7-(piperazin-1-yl)-1,4-dihydro-quinoline-3-carboxyl-ato-κN:O,O] tetra-hydrate].

In the title compound, {[Cu(C(16)H(17)FN(3)O(3))(2)]·4H(2)O}(n), the Cu(II) atom is bonded to two O,O'-bidentate 1-ethyl-6-fluoro-4-oxo-7-(piperazin-1-yl)-1,4-dihydro-quinoline-3-carboxyl-ate (norf) monoanions and a symmetry-generated N-bonded norf anion, resulting in a distorted square-pyramidal coordination environ-ment with the N atom occupying the apical site. The bridging norf anion results in one-dimensional chains propogating along [010]. A network of O-H⋯O and N-H⋯O hydrogen bonds helps to establish the crystal structure.