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-tetra­yltetra­kis­(methyl­ene)]tetra­kis­(N-methyl­aniline)

The whole molecule of the cadmium(II) complex, diiodido{N,N0 ,N00,N000- [pyrazine-2,3,5,6-tetrayltetrakis(methylene)]tetrakis(N-methylaniline)- 3 N2 ,N1 ,N6 }cadmium(II), [CdI2(C36H40N6)], (I), of the ligand N,N0 ,N00,N000- [pyrazine-2,3,5,6-tetrayltetrakis(methylene)]tetrakis(N-methylaniline) (L), is generated by a twofold rotation symmetry; the twofold axis bisects the cadmium atom and the nitrogen 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,N0 ,N00,N000-[pyrazine-2,3,5,6-tetrayltetrakis(methylene)]tetrakis(Nmethylaniline)-3 N2 ,N1 ,N6 }zinc(II) dichloromethane 0.6-solvate, [ZnCl2(C36H40N6)]0.6CH2Cl2, (II), ligand L also coordinates in a monotridentate manner and the zinc atom has a fivefold ZnN3Cl2 coordination environment with a distorted shape. It crystallized as a partial dichloromethane solvate. In the crystal of I, the complex molecules are linked by weak C—HI contacts, forming ribbons propagating along [100]. In the crystal of II, the complex molecules are linked by a series of C—H interactions, forming layers lying parallel to the (111) plane. In the crystals of both compounds there are metal–halide(pyrazine) contacts present. The Hirshfeld analyses confirm the importance of the C—Hhalide contacts in the crystal packing of both compounds.