MULTIPLE BONDS BETWEEN MAIN-GROUP ELEMENTS AND TRANSITION-METALS .137. POLYMERIC METHYLTRIOXORHENIUM - AN ORGANOMETALLIC NANOSCALE DOUBLE-LAYER STRUCTURE OF CORNER-SHARING REO5(CH3) OCTAHEDRA WITH INTERCALATEDWATER-MOLECULES

A two-dimensional structural model of polymeric methyltrioxorhenium (M TO) has been established by means of diffraction techniques and a vari ety of analytical methods. The unusual compound, constituting the firs t example of a polymeric organometallic oxide, has a layer structure o f methyl-deficient, comer-sharing ReO5(CH3) octahedra. It adopts the t hree-dimensional extended ReO3 motif in two dimensions as a {ReO2}infi nity network. Adjacent layers of corner-sharing ReO5(CH3) octahedra (A ) are capable of forming staggered double layers (AA'). In the crystal line areas of ''poly-MTO'', such double layers are separated by interc alated water molecules (monolayer) (B) with an ...AA'BAA'... layer seq uence. For the partially amorphous areas of ''poly-MTO'', we propose a turbostratic and 00l-defect stacking model for the ''poly-MTO'' and w ater layers. Interactions between the adjacent layers in this polymeri c MTO are very weak, resulting in graphite-like macroscopic properties such as flaky appearance, softness, and lubricity. High electric cond uctivity results from understoichiometry with respect to the CH3/Re ra tio (9.2/10) and partial reduction by extra hydrogen equivalents. For the purpose of comparison, the solid-state structure of ''monomeric'' MTO as established by a combination of X-ray and powder neutron diffra ction techniques is also reported.