Aqua-bis(2,2′-bipyridine-k2 N,N′)(1H-indole-2- carboxyl-ato-kO)nickel(II) 1H-indole-2-carboxyl-ate dihydrate

The hydro-thermal reaction of Ni2(OH)2CO3 with 2,2′-bipyridine and 2-indolyl-formic acid in CH3OH/H2O at 423 K for 7 d produced the novel Ni II complex [Ni(C9H6NO2)(C10H8N2)2(H2O)](C9H6NO2)·2H2O. The asymmetric unit of the title compound consists of a monovalent [Ni(L)(bpy)2(H2O)]+ 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(H2O)]+ 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 NiN4O2 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.