Synthese und Kristallstruktur von (PPh4)2[Mo2(O2C—Ph)4Cl4] · 2 CH2Cl2, einem Komplex mit Mo≡Mo-Bindung / Synthesis and Crystal Structure of (PPh4)2[Mo2(O2C —Ph)4Cl4] ·2 CH2Cl2, a Complex with Mo≡Mo Bonding

Abstract

The title compound has been prepared from (PPh4)2[Mo2(O2C-Ph)4Cl2] and CCl4 in CH2Cl2 solution as moisture sensitive crystals, which are black in reflexion and yellow in transmission. (PPh4)2[Mo2(O2C-Ph)4Cl4] · 2 CH2Cl2 was characterized by a X-ray crystal structure determination (7873 observed independent reflexions. R = 0.048). It crystallizes in the space group P1̄ with one formula unit in the unit cell; the lattice constants are a = 1186.4; b = 1404.0; c = 1451.0 pm; α = 61.98°; β = 78.91°; γ = 78.26°. The structure consists of PPh4 ⊕ ions. CH2Cl2 molecules and centrosymmetric anions [Mo2(O2C-Ph)4Cl4]2⊝ containinga molybdenum d3 d3 unit with a relatively long Mo=Mo bond of 249.6 pm. The Mo≡Mo group is spanned in a chelate manner by four O atoms of two benzoate groups and by two further single O atoms of two further benzoate groups. Two terminal Cl atoms on each Mo atom complete the pentagonal bipyramidal coordination spheres about the Mo atoms.