Aqua-bis(2,2'-bipyridine-κN,N')(1H-indole-2-carboxyl-ato-κO)nickel(II) 1H-indole-2-carboxyl-ate dihydrate.

The hydro-thermal reaction of Ni(2)(OH)(2)CO(3) with 2,2'-bipyridine and 2-indolyl-formic acid in CH(3)OH/H(2)O at 423 K for 7 d produced the novel Ni(II) complex [Ni(C(9)H(6)NO(2))(C(10)H(8)N(2))(2)(H(2)O)](C(9)H(6)NO(2))·2H(2)O. The asymmetric unit of the title compound consists of a monovalent [Ni(L)(bpy)(2)(H(2)O)](+) cation (bpy is 2,2'-bipyridine and L is 1H-indole-2-carboxyl-ate), an L anion and two solvent water mol-ecules. In the [Ni(L)(bpy)(2)(H(2)O)](+) cations, the Ni atom coordinates to four N atoms from the two bpy ligands and two O atoms, one from a L anion and the other from a water mol-ecule to complete an significantly distorted NiN(4)O(2) octa-hedron. The coordinated and solvate water mol-ecules form an extensive series of O-H⋯O hydrogen bonds. N-H⋯O and C-H⋯O hydrogen bonds are also present and the mol-ecules are inter-linked, forming a three-dimensional network.