Experimental

R factor = 0.024; wR factor = 0.066; data-to-parameter ratio = 17.0. In the title adduct, [ZnCl2(C4H5N3)2], the Zn II atom lies on a twofold rotation axis that relates one Cl atom to the other as well as one 2-aminopyrazine ligand to the other; the coordination geometry is a distorted tetrahedron. In the crystal, adjacent molecules are linked by N—H N hydrogen bonds across the center of inversion, generating a chain; neighboring chains are linked by N—H Cl hydrogen bonds, forming a three-dimensional network. Related literature For a related compound, CoCl2(C4H5N3)4, see: Kang et al