摘要 |
<p>An improved olefin metathesis catalyst system comprises a tungsten halide having an average of no more than about one halide substituent and no more than one oxygen substituent per tungsten with the remaining tungsten valences satisfied with phenolic substituants incorporating at least one meta or para electron withdrawing group and a triorganotin hydride and, optionally, a boron halide promoter. The catalyst system forms a relatively stable polymerization mixture with polycycloolefins and effectively polymerizes dicyclopentadiene in the presence of water.</p> |