pi -COMPLEX COMPOUNDS

摘要

pi -complex compounds and in particular metallocene compounds of formula (Ia)(Ib), in which pi I and pi II represent pi -systems, D designates a donor atom and A designates an acceptor atom, D and A being linked by a reversible coordinative bond such that the donor group assumes a positive (partial) charge and the acceptor group assumes a negative (partial) charge, at least one of D and A being part of the associated pi -system in each case, M stands for a transition metal of the 3rd, 4th, 5th or 6th subgroup of the (Mendelian) periodic system of elements, X designates an anion equivalent and n designates the number zero, one, two, three of four depending on the charges of M and those of pi I and pi II, are novel and can be used as catalysts for the (co)polymerization of olefins, i-olefins, alkines and/or diolefins or for ring-opening polyaddition.