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Ring opening metathesis polymerization (ROMP) is the key process for the preparation of various industrial polyalkenamers (e.g. Norsorex). The reaction has been extensively studied. A variety of catalytic systems have been used, based mainly on mononuclear transition metal complexes. Imetallic metal-metal bonded complexes have been rarely employed. However, despite the considerable progress, there are still severe drawbacks with the most reactive ones, which prevent their use in industry. Thus, the search for more practical catalysts remains a challenge.
Recently, research team 1 has discovered a new generation of efficient and selective catalysts based on complexes Na4[W2Cl8] (THF)x (1, W 4 W)4+) and Na[W2(?-Cl)3Cl4(THF) (THF)3 (2, W 3 W)6+), which catalyze the metathetical polymerization of monosubstituted alkynes and the ROMP of norbornene. An interesting aspect of these initiators is their marked predilection to produce highly cis-polyacetylenes, which is unusual within the single-component tungsten halide analogues.
Among the specific aims of the proposed research are the improvement of catalysts 1,2 in terms of stability and the development of new selective catalysts deriving from structurally analogous multiply bonded complexes (Mo, W, Re, Ru) with various ligands (phosphines, porphyrins), as well as the elaborate study of their reactivity in ROMP reactions of industrial importance.
Novel multifunctional materials will be synthesized and studied:
- macromolecular architectures, by combining living and controlled polymerization techniques,
- polymers with predetermined properties, deriving from the (co)polymerization of special cycloolefins and if necessary, postmodification, and
- polymer-crosslinked aerogels with improved properties.
In addition, the collaboration of research groups internationally recognized in different fields (Catalysis, Polymers, Materials) will be enhanced.
ROMPADMAT/377252
