Copper(II) Complexes with Chiral Ligands Containing Fragments of Monoterpenoids and Amino Acid Esters

Complexes [CuL 1 Cl 2 ] ( I ), [CuL 2 Cl 2 ] · EtOH ( II ), and Cu 2 L 3 Cl 4 (III) containing esters of the N-derivatives of optically active amino acids based on (+)-3-carene (L 1 , L 2 ) and (‒)-α-pinene (L 3 ) are synthesized. The crystal and molecular structures of compounds I and II are determined by X-ray diffraction analyses (CIF files CCDC nos. 1560071 ( I ), 1560072 ( II )). The crystal structure of compound I consists of mononuclear complex molecules. In the structure of compound II , the unit cell contains two crystallographically independent molecules of mononuclear complex [CuL 2 Cl 2 ] and two EtOH molecules. Ligands L 1 and L 2 perform the tridentate-chelating function by the N atoms of the NH and NOH groups and by the O atom of the C=O group. In compounds I and II , the coordination polyhedra Cl 2 N 2 O of the Cu atoms are trigonal bipyramid. According to the data of IR and electronic spectroscopy, binuclear complex III has similar coordination polyhedra. The experimental values of μ eff for compounds I , II , and III at 300 K are 1.93, 1.88, and 2.71 μB. For complex III, the μ eff ( T ) dependence in a range of 2–300 K indicates a weak ferromagnetic exchange interaction.