Cu(II) complexes with chiral ethylenediaminodioxime and propylenediaminodioxime, the derivatives of monoterpenoid α-pinene:: Synthesis and structures

Copper(II) complexes with chiral ethylenediaminodioxime (H2L1) and propylenediaminodioxime (H2L2), the derivatives of terpenoid alpha-pinene, of the composition [Cu(H2L1)](NO3)(2) (I) and [Cu(H2L2)NO3]NO3 (II) are synthesized and studied by X-ray diffraction method. The ionic structures of I and II consist of complex cations [Cu(H2L1)](2+) (I), [Cu(H2L2)NO3](+) (II), and outer-sphere anions NO3-. In the cation of compound I, the Cu2+ ion (C.N. 4) coordinates four N atoms of tetradentate cycle-forming ligand H2L1 with anti-configuration. The coordination surrounding of the Cu atom is a trapezoidally distorted square. In the cation of compound II, the Cu2+ ion (C.N. 5) coordinates the O atom of monodentate nitro group in addition to four N atoms of tetradentate cycle-forming ligand H2L2. The coordination polyhedron of the Cu atom has the shape of a distorted square pyramid N4O. Coordinated H2L2 molecule has amphi-configuration, which is responsible for the formation of hydrogen bond between the oxime groups. The complex cations and NO3- anions in structures I and II are linked into ionic ensembles by hydrogen bonds.