New Organometallic Polymers Containing Tungsten Carbene Complexes¹

Inorganic and organometallic polymers containing transition metals, lanthanides, or main-group elements (P, Si, Sn, Li, or Pb) are a very intriguing group of materials and are currently receiving considerable attention.² These polymers have many useful applications as chemically resistant elastomers,³ reagents for organic synthesis,⁴ catalysts,⁵ antifouling agents,⁶ electroactive films,⁷ metal-polymer composites,⁸ positive resists in microlithography,⁹ or precursors to ceramics.¹⁰ Most transition-metal organometallic polymers have been prepared by three methods: (1) chain polymerization of vinyl monomers,^2g(2) step-growth polymerization of bifunctional monomers,^28,11 or (3) modification of preformed polystyrene resins.⁵ Among the various transition-metal-containing vinyl monomers prepared and polymerized^28,f,g are derivatives of cyclopentadienyl-metal complexes, styryl-metal systems, or diene-metal complexes in which the vinyl groups are connected to cyclopentadienyl ligands, arene rings, or diene ligands, respectively. To our knowledge, there is only one other account of polymeric materials that contain transition-metal carbene complexes.^12,13 We now report on the polymerization of the tungsten-car bene vinyl monomer 1, which affords the first polymeric material 2 to contain repeating transition-metal carbene fragments, the characterization of this new polymer, and some initial findings dealing with its reactivity.