Polymerization of acrylates by neutral palladium complexes. Isolation of complexes at the initial steps

The polymerization of methyl acrylate by pentafluorophenyl complexes [Pd2(μ-X)2(C6F5)2L2] (L = tetrahydrothiophene (tht), X = Cl, 2; L = tht, X = Br, 3; L = AsPh3, X = Br, 4) gives atactic polymers...