Electron-poor olefin polymerization catalysts based on Semi-fluorinated bis(phosphane)s

Two semi-fluorinated bis(phosphane)s, P,P'-(1,2-ethanediyl)bis[bis(2,4,5-tr ifluorophenyl)phosphane] (3a), P,P'-(1,2-ethanediyl)bis[bis(2,4-difiuorophe nyl)phosphphane] (3b) and their corresponding Pd-II- and Pt-II-dichloro com plexes (4a,b and 6a,b) have been synthesized. Complexation of P,P'-(1;2-eth anediyl)bis(bis[3,5-di(trifluoromethyl)phenyl]phosphane) (3c) and P, P'-(1, 2-ethanediyl)bis[bis (pentafluorophenyl)phosphane] (3d) afforded the relat ed compounds 4c,d and 6c. The Pd-II-diiodo complexes 5c,d have been obtaine d from 4c,d by halide exchange with NaI. The solid-state structures of comp ounds 4b and 5c,d have been determined by single-crystal X-ray diffraction analysis. Activation of 4b-d with MAO produced efficient catalysts for the polymerization of 2-norbornene, which have proved to be superior to the Pd- II-dichlorides derived from the more electron-rich, structurally related P, P'-(1,2-ethanediyl)bis(diphenylphosphane) (DPPE) or P,P'-(1-3-propanediyl)b is(diphenylphosphane) (DPPP).