New platinum(II) complexes with benzothiazole ligands

Four new platinum(II) complexes, namely tetraethylammonium tribromido(2-methyl-1,3-benzothiazole-kappa N) platinate(II), [NEt4][PtBr3(C8H7NS)] (1), tetraethylammonium tribromido(6-methoxy-2-methyl-1,3-benzothiazole-kappa N)-platinate(II), [NEt4][PtBr3(C9H9NOS)] (2), tetraethylammonium tribromido-(2,5,6-trimethyl-1,3-benzothiazole-kappa N) platinate(II), [NEt4][PtBr3(C10H11NS)] (3), and tetraethylammonium tribromido(2-methyl-5-nitro-1,3-benzothiazole-kappa N) platinate(II), [NEt4][PtBr3(C8H6N2O2S)] (4), have been synthesized and structurally characterized by single-crystal X-ray diffraction techniques. These species are precursors of compounds with potential application in cancer chemotherapy. All four platinum(II) complexes adopt the expected square-planar coordination geometry, and the benzothiazole ligand is engaged in bonding to the metal atom through the imine N atom (Pt-N). The Pt-N bond lengths are normal: 2.035 (5), 2.025 (4), 2.027 (5) and 2.041 (4) angstrom for complexes 1, 2, 3 and 4, respectively. The benzothiazole ligands are positioned out of the square plane, with dihedral angles ranging from 76.4 (4) to 88.1 (4)degrees. The NEt4 cation in 3 is disordered with 0.57/0.43 occupancies.