Bis(2,2′-bipyridine-κ2 N,N′)bis­(1H-indole-2-carboxyl­ato-κ2 O,O′)cadmium–2,2′-bipyridine–water (1/0.5/2)

The asymmetric unit of title compound, [Cd(C(9)H(6)NO(2))(2)(C(10)H(8)N(2))(2)]·0.5C(10)H(8)N(2)·2H(2)O, consists of one complex mol-ecule, one half of an uncoordinated 2,2'-bipyridine mol-ecule and two solvent water mol-ecules. The uncoordinated 2,2'-bipyridine mol-ecule is located on a center of symmetry. Within the complex mol-ecule, the Cd(II) atom is coordinated by four N atoms from two 2,2'-bipyridine ligands and three O atoms from two 1H-indole-2-carboxyl-ate anion ligands, completing a distorted CdN(4)O(3) penta-gonal bipyra-mid. The mol-ecules are assembled into one-dimensional chains along the [100] direction through classical hydrogen bonds (O-H⋯N, N-H⋯O and O-H⋯O). The resulting chains are further connected into two-dimensional supra-molecular layers parallel to the (110) direction by inter-molecular classical hydrogen bonds (N-H⋯O and O-H⋯O) from adjacent chains. A three-dimensional supra-molecular network is formed via interlayer and O-H⋯O hydrogen bonds.