The crystal structures and Hirshfeld surface analyses of a cadmium(II) and a zinc(II) mononuclear complex of the new tetrakis-substituted pyrazine ligand N,N',N'',N'''-[pyrazine-2,3,5,6-tetra-yltetra-kis-(methyl-ene)]tetra-kis-(N-methyl-aniline).

The whole mol-ecule of the cadmium(II) complex, di-iodido-{N,N',N'',N'''-[pyrazine-2,3,5,6-tetra-yltetra-kis-(methyl-ene)]tetra-kis-(N-methyl-aniline)-κ3 N 2,N 1,N 6}cadmium(II), [CdI2(C36H40N6)], (I), of the ligand N,N',N'',N'''-[pyrazine-2,3,5,6-tetra-yltetra-kis-(methyl-ene)]tetra-kis-(N-methyl-aniline) (L), is generated by a twofold rotation symmetry; the twofold axis bis-ects the cadmium atom and the nitro-gen atoms of the pyrazine ring. The ligand coordinates in a mono-tridentate manner and the cadmium atom has a fivefold CdN3I2 coordination environment with a distorted shape. In the zinc(II) complex, dichlorido{N,N',N'',N'''-[pyrazine-2,3,5,6-tetra-yltetra-kis-(methyl-ene)]tetra-kis-(N-methyl-aniline)-κ3 N 2,N 1,N 6}zinc(II) di-chloro-methane 0.6-solvate, [ZnCl2(C36H40N6)]·0.6CH2Cl2, (II), ligand L also coordinates in a mono-tridentate manner and the zinc atom has a fivefold ZnN3Cl2 coordination environment with a distorted shape. It crystallized as a partial di-chloro-methane solvate. In the crystal of I, the complex mol-ecules are linked by weak C-H⋯I contacts, forming ribbons propagating along [100]. In the crystal of II, the complex mol-ecules are linked by a series of C-H⋯π inter-actions, forming layers lying parallel to the (11) plane. In the crystals of both compounds there are metal-halide⋯π(pyrazine) contacts present. The Hirshfeld analyses confirm the importance of the C-H⋯halide contacts in the crystal packing of both compounds.