Synthesis, structure, and bonding of fulvene complexes of titanium, molybdenum, and tungsten

Abstract

The compounds [M(η-C₆H₅R)(σ,η⁵-C₅H₄CR′₂)](M = Mo or W, R = H, R′= Me or Ph; M = W, R = Me, R′= Me or Ph), [W(η-C₆H₃Me₃-1,3,5)(σ,η⁵-C₅H₄CPh₂)], [Ti(σ,η⁵-C₅H₄CPh₂)₂], and [Ti(σ,η⁵-C₅H₄CPh₂)₂(CO)] are described. The crystal structures of the compounds where M = Mo, R = H, R′= Me or Ph; M = W, R = Me, R′= Me or Ph; and [Ti(σ,η⁵-C₅H₄CPh₂)₂] have been determined and reveal that the exocyclic carbon of the fulvene ligands is strongly bent out of the plane of the C₅-ring carbons and bonds directly to the metal. The metal–fulvene bonding is discussed in the light of the structures, the photoelectron spectra, and molecular orbital calculations.