<i>catena</i>-Poly[[[(1-ethyl-6-fluoro-4-oxo-7-(piperazin-1-yl)-1,4-dihydroquinoline-3-carboxylato-κ<sup>2</sup> <i>O</i> <sup>3</sup>,<i>O</i> <sup>4</sup>)copper(II)]-μ-1-ethyl-6-fluoro-4-oxo-7-(piperazin-1-yl)-1,4-dihydroquinoline-3-carboxylato-κ<sup>3</sup> <i>N</i> <sup>7′</sup>:<i>O</i> <sup>3</sup>,<i>O</i> <sup>4</sup>] tetrahydrate]
Acta crystallographica. Section E