SYNTHESIS AND CRYSTAL STRUCTURE OF THE MOLECULES OF 1-(2-BENZOTHIAZOLYL)-3,5-DIMETHYLPYRAZOLE C12H11N3S AND DIOXODICHLOROMOLYBDENUM(VI)

Article abstract of DOI:10.1007/BF00752551

The synthesis and X-ray crystallographic investigation of the molecule of 1-(2-benzothiazolyl)-3,5-dimethylpyrazole, L (I), and the molecular complex MoO2Cl2*L (II) were undertaken .The crystals of (I) are rhombic with a = 17.797, b = 10.836, c = 12.172 Angstroem, d_det = 1.38 g/cm³, Z = 8, space group Pcab; the crystals of (II) are monoclinic with a = 10.305, b = 11.927, c = 12.825 Angstroem, β = 92.53 deg, d_det = 1.81, Z = 4, space group P2₁/n.The molecule of L in (I) has the s-trans conformation.During complexation with molybdenum the benzothiazole ring of the ligand L in (II) is rotated about the C(1)-N(2) bond by ca. 180 deg C.In the complex (II) the Mo atom has a distorted octahedral coordination with the cis structure for the dioxo group, as in other complexes of the d⁰ metals of groups V-VIII.The N(1) atom of the benzothiazole and N(3) atom of the pyrazole ring of the bidentate ligand L occupy the trans positions to the oxo atoms.The five-membered metallocycle MoN3C has the emvelope conformation with the Mo "corner" bent from the plane of the N(1-3) and C(1) atoms by 0.132 Angstroem.The average bond lengths in (II) are: Mo-O 1.685, Mo-Cl 2.357, Mo-N 2.310 Angstroem.As usual, the Mo-N bonds are elongated as a result of the trans effect of the multiply bonded oxo ligands.