Reactions of 1-Titana- and 1-Zirconacyclopent-3-ynes with Tris(pentafluorophenyl)borane
摘要:
The 1-metallacyclopent-3-ynes Cp2Ti(eta(4)-H2C4H2) (1) (Cp = eta(5)-cyclopentadienyl) and rac-(ebthi)Zr(eta(4)-H2C4H2) (2) (ebthi = 1,2-ethylene-1,1'-bis(eta(5)-tetrahydroindenyl) react with B(C6F5)(3) under ring opening of the metallacycle and formation of the zwitterionic complexes [Cp2Ti](+)-CH2C CCH2-[B-(C6F5)(3)] (3) and [rac-(ebthi)Zr](+)-CH2C CCH2-[B-(C6F5)(3)] (4). Crystal structures of 3 and 4 show a but-2-yne-1,4-diyl ligand bridging the metallocenium center and the formed boranate. Complex 4 is an active catalyst for ethylene polymerization.