Crystal structure of catena-poly[[copper(II)-μ(2)-salicylato-[diaqua-copper(II)]-μ(2)-salicylato] dihydrate].

The title compound, {[Cu(2)(C(7)H(4)O(3))(2)(H(2)O)(2)]·2H(2)O} (n) , contains two copper(II) cations in special positions (one on a twofold rotation axis and one on an inversion centre) and the the salicylate ligand in its dianionic form. By four- and six-coordinate metal coordination, chains are formed parallel to [001], which are extended by O-H⋯O hydrogen bonding into sheets extending parallel to (100). These sheets are weakly connected by O-H⋯O hydrogen bonding via the non-coordinating lattice water mol-ecules into a three-dimensional network.