The Ni atom in the title compound, [Ni(C(17)H(15)N(2)O)(2)]·2C(3)H(7)NO, lies on a twofold rotation axis. It is N,O-chelated by the deprotonated Schiff base 2-[2-(1H-indol-3-yl)ethyl-imino-meth-yl]phenolate ligand in a square-planar coordination environment. The mol-ecule is linked to a solvent mol-ecule by an indole-dimethyl-formamide N-H⋯O hydrogen bond.
The title Schiff base, C(17)H(15)N(3)O(3), exists in the zwitterionic form with the phenol H atom transferred to the imine group. Adjacent zwitterions are linked into a linear chain running along the a axis by an indole-hydr-oxy N-H⋯O hydrogen bond [3.100 (2) Å].
The Zn atom in the title compound, [Zn(C(17)H(14)ClN(2)O)(2)], is N,O-chelated by two deprotonated Schiff base monoanionic ligands in a tetra-hedral coordination geometry. The Zn atom lies on a special position of site symmetry 2.
In the mononuclear complex mol-ecule of the title compond, [ZnCl(2)(C(18)H(18)N(2)O)(2)]·2C(18)H(18)N(2)O, the Zn atom, which lies on a twofold rotation axis, is coordinated by phenolate O atoms in a tetra-hedral coordination geometry. The coordinated Schiff base uses its indole NH donor site to form a hydrogen bond to the negatively charged phenolate O atom of the uncoordinated zwitterionic Schiff base. There is an intra-molecular N-H⋯O hydrogen bond in the coordinated and uncoordinated Schiff bases. The indole NH site of the uncoordinated Schiff base does not engage in a hydrogen-bond inter-action. The CH(2)-CH(2) group in the uncoordinated Schiff base is disordered equally over two positions.