Two new platinum complexes containing a chelating safrole-derivative and amine

Abstract

A series of new platinum(II) complexes containing chelating safrole (or its derivatives) and various amines have been synthesized to evaluate their anticancer activity. Here we report the structure determination of [Pt((MeO)2Ph)(o-toluidine)Cl] (1) and [Pt((MeO)2Ph)(piperidine)Cl] (2), with (MeO)2Ph 3,4-dimethoxyphenyl-2-propene. Plate-like crystals of (1), suitable for x-ray diffraction measurement were obtained by slow evaporation from an ethanol solution. Rod-like crystals of (2) were harvested from ethanol after slow evaporation of acetone from an ethanol-acetone solution. Diffraction data were collected on a diffractometer equipped with a Bruker-AXS SMART 6000 CCD detector and integrated by the program SAINT. A multi-scan absorption correction was performed by the program SADABS. Both structures were solved by direct methods using the SHELXS program and refined according to the least-squares method to R-values of for 0.0204 (1) and 0.0280 for (2). The crystal of (1) to the orthorhombic space group P212121 and that of (2) belongs to the triclinic space group P-1. The asymmetric unit of (1) comprises one molecule of [Pt((MeO)2Ph)(o-toluidine)Cl]. The asymmetric unit of (2) consists of one ethanol molecule and one [Pt((MeO)2Ph)(piperidine)Cl] molecule. Both structures are similar with respect to the configuration and geometry of the Pt complex. Considering the centroid Cg of the allyl C=C bond as one ligand, the coordination geometry of Pt is square planar (other ligands are Cl, N (amine) and C (phenyl ring)). The angle between the best planes through the (MeO)2Ph and amine ligands is 84.3(1)0in (1) and 25.2(5)0in (2). The best plane through the allyl group makes an angle of 55.6(2)0and 56.4(4)0with the best plane through the (MeO)2Ph group, respectively in (1) and (2). The allyl double bond C=C is nearly perpendicular to Pt–Cg line, 89.8(2)0in (1) and 87.4(8)0in (2). For (1) the packing is essentially the result of van der Waals' interactions and two weak hydrogen bonds of type C-H...Cl and C-H...O. In (2) the packing is determined by the O-H...O hydrogen bond (O...O distance 2.870(4) Å) between ethanol and one of the methoxy substituents.