Über die Reduktion von Alkinkomplexen des Molybdäns und Wolframs in hohen Oxidationsstufen. Die Kristallstruktur von MoCl3(THF)3 / On the Reduction of Alkyne Complexes of Molybdenum and Tungsten in High Oxidation States. The Crystal Structure of MoCl3(THF)3

Abstract

The reduction of the tungsten alkyne complexes [WCl4(RC≡CR)]2 (R = Ph, SiMe3) with cobaltocen in THF solutions leads to the complexes [CoCp2]2[WCl4(RC≡CR)]2 (R = Ph (1); R = SiMe3 (2)), as green, oxygen sensitive crystalline powders. Reduction of [WCl4(Me3SiC=CSiMe3)]2 and of [MoCl4(PhC=CPh)]2 with sodium naphthalide in THF solutions in the presence of 15-crown-5 gives [Na-15-crown-5]3[W2Cl9], and MoCl3(THF)3, respectively. All compounds have been characterized by IR spectroscopy, and 1 and 2, in addition, by their EPR spectra. The crystal structure of MoCl3(THF)3 was determined by X-ray methods. Space group P21/c, Z = 4, 2642 observed unique reflexions, R = 0.050. Lattice dimensions at 20 °C: a = 888.4(2), b = 1281.5(3), c = 1535.2(3) pm, β = 92.17(2)°. The compound forms monomeric octahedral molecules with a meridional arrangement of the ligands.