(Dimethyl sulfoxide-κO){4,4',6,6'-tetra-tert-butyl-2,2'-[1,2-dicyano-ethene-1,2-diylbis(nitrilo-methyl-idyne)]diphenolato-κO,N,N',O'}zinc(II) acetonitrile monosolvate.

The Zn atom in the title acetonitrile solvate, [Zn(C(34)H(42)N(4)O(2))(C(2)H(6)OS)]·CH(3)CN, exists in a distorted square-pyramidal geometry with the basal plane defined by the N(2)O(2) atoms of the tetra-dentate Schiff base and with the dimethyl sulfoxide O atom in the apical position. The tetra-dentate mode of coordination of the Schiff base ligand leads to a five-membered ZnN(2)C(2) chelate ring which adopts an envelope conformation with the Zn atom at the flap, and two six-membered ZnOC(4)N chelate rings, one of which is approximately planar (r.m.s. deviation = 0.054 Å) but the other has significant puckering (r.m.s. deviation = 0.203 Å).

8-[(1E)-1-(2-Aminophenyl-iminio)eth-yl]-2-oxo-2H-chromen-7-olate.

The title Schiff base, C(17)H(14)N(2)O(3), exists as an NH tautomer with the H atom of the phenol group transferred to the imine N atom. The iminium H atom is involved in a strong intra-molecular N(+)-H⋯O(-) hydrogen bond to the phenolate O atom, forming an S(6) motif. In the crystal structure, N-H⋯O hydrogen bonds form a C(9) chain parallel to [100] and a C(11) chain parallel to [010], while C-H⋯O hydrogen bonds form a C(11) chain parallel to [010]. The combination of N-H⋯O and C-H⋯O hydrogen bonds generates R(4) (3)(30) rings parallel to the ab plane.