W2Cl7(CCl), a Polymeric Tungsten Chlorocarbyne Complex

Black crystals of W₂Cl₇(CCl) were obtained from the reaction of WCl₆ and As in CCl₄ at 250 °C under solvothermal conditions. The crystal structure (orthorhombic, space group Pbca, a = 1196(1), b = 1215.6(7), c = 1584(1) pm, Z = 8) is built of infinite zig‐zag chains of dinuclear complexes connected via bridging Cl atoms. The individual complexes are face‐sharing double octahedra concatenated via bridging Cl ligands. Each W atom is in a distorted octahedral coordination environment of five Cl atoms an the carbon atom of the μ₂ bridging chloromethylidyne ligand leading to the formula {Cl₂W(μ‐CCl)(μ₂‐Cl)₂WCl₂}(μ‐Cl)]_n. The short W‐W distance of 256 pm indicates a multiple W‐W bond, the W‐C bonds of 195 pm are in the typical range for μ₂‐alkylidyne ligands, the C‐Cl bond of 167 pm is consistent with a sp¹ hybridisation on the carbon atom.