Cobalt(II) and copper(II) complexes with chiral pyrazolylquinoline,a derivative of terpenoid (+)-3-carene. Catalytic activity in ethylene polymerization reaction

Coordination compounds CoLCl₂] (I), CuLCl(NO₃)] (II), CuL(NO₃)₂ (III), and CuLCl₂ (IV) (where L is a chiral pyrazolylquinoline—a derivative of terpenoid (+)-3-carene) were synthesized. X-ray diffraction data showed that crystal structures I and II are built of mononuclear acentric molecules. In the molecule of complex I, the Co₂₊ ion coordinates two N atoms of bidentate cycle-forming ligand L and two Cl atoms. The coordination polyhedron of Cl₂N₂ is a distorted tetrahedron. For complex I, μ_eff = 4.50 μ_B, which corresponds to a high-spin configuration d ⁷. In the molecules of II(1), II(2) (which are diastereoisomers of complex II), each Cu²⁺ ion coordinates two N atoms of bidentate cycle-forming ligand L, the Cl atom, and two O atoms of bidentate cyclic NO ₃ ^? ion. The ClN₂O₂ coordination polyhedra are tetragonal pyramids with different degrees of distortion. The structure of complex II consists of supramolecular clusters, i.e., isolated chains incorporating the molecules of II(1) and II(2). The values of μ_eff for II–IV correspond to the d ⁹ configuration. The results of EPR and IR study suggest that complex III contains the O₄N₂ polyhedron, whereas complex IV contains the Cl₂N₂ polyhedron. Complexes I and IV were found to show a high catalytic activity in ethylene polymerization reaction.