Synthesis and structure of Cu(II) and Pd(II) coordination compounds with chiral α-thiooxime, a derivative of natural terpenoid (-)-α-pinene

The paramagnetic complex Cu(HL)Cl-2(I) (mu(eff) = 1.88 mu(B)) and the diamagnetic complex Pd(HL)Cl-2(II) with chiral alpha-thiooxime, a derivative of natural terpenoid (-)-alpha-pinene (HL), were synthesized. The crystal structures of these complexes were determined from single-crystal X-ray diffraction data (X8 APEX diffractometer, MoK alpha radiation, 2975 F-hkl , R = 0.0258 for I and 3270 F-hkl , R = 0.0222 for II). The crystals of complex I are monoclinic, a = 9.3376(3) angstrom, b = 6.8619(2) angstrom, c = 14.6540(5) angstrom, beta = 97.814(1)degrees, V = 930.22(5) angstrom(3), Z = 2, rho(calc) = 1.513 g/cm(3), space group P2(1). The crystals of complex II are orthorhombic, a = 7.0084(6) angstrom, b = 9.2113(9) angstrom, c = 29.081(3) angstrom, V = 1877.4(3) angstrom(3), Z = 4, rho(calc) = 1.651 g/cm(3), space group P2(1)2(1)2(1). The structures are composed of mononuclear molecules. The coordination cores MNSCl2 (M = Cu, Pd) are tetrahedrally distorted squares. According to NMR data, complex II has a similar structure in a CDCl3 solution. The intermolecular contacts in structure I generate supramolecular polymeric ribbons lying parallel to axis b. No short intermolecular contacts are present in complex II.