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)

Abstract

The whole molecule of the cadmium(II) complex, diiodido{N,N′,N′′,N′′′-[pyrazine-2,3,5,6-tetrayltetrakis(methylene)]tetrakis(N-methylaniline)-κ3N2,N1,N6}cadmium(II), [CdI2(C36H40N6)], (I), of the ligand N,N′,N′′,N′′′-[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,N′,N′′,N′′′-[pyrazine-2,3,5,6-tetrayltetrakis(methylene)]tetrakis(N-methylaniline)-κ3N2,N1,N6}zinc(II) dichloromethane 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 dichloromethane solvate. In the crystal of I, the complex molecules are linked by weak C—H...I contacts, forming ribbons propagating along [100]. In the crystal of II, the complex molecules are linked by a series of C—H...π interactions, forming layers lying parallel to the (1\overline{1}1) 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.

Keywords

• crystal structure
• tetrakis-substituted pyrazine
• cadmium(ii)
• zinc(ii)
• mononuclear complexes
• c—h...π interactions
• metal–halide...π(pyrazine) contacts