Aquabis(2,2′-bipyridine-κ²N,N′)(1H-indole-2-carboxylato-κO)nickel(II) 1H-indole-2-carboxylate dihydrate

The hydrothermal 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 NiII 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-carboxylate), an L anion and two solvent water molecules. 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 molecule to complete an significantly distorted NiN4O2 octahedron. The coordinated and solvate water molecules form an extensive series of O—H...O hydrogen bonds. N—H...O and C—H...O hydrogen bonds are also present and the molecules are interlinked, forming a three-dimensional network.