Bulk Coordination Polymerization of Dicyclopentadiene (DCPD) by Pd Complexes Containing β-Ketoiminate or β-Diketiminate Ligands

Several palladium complexes containing beta-ketoiminate and beta-diketiminate ligands successfully produced poly(DCPD) possibly via vinyl addition. It was found that catalysts with beta-diketiminate ligands containing bulkier aryl substituents showed the highest activity in the presence of MAO as a cocatalyst. Purity of DCPD is quite essential for the higher activity and small amount of organic solvent such as CH2Cl2 and toluene is required to reduce the viscosity of the reactant mixture for the higher activity. H-1 NMR spectra of produced polymers with N,N-dimethylanilinium tetra(pentafluorophenyl)borate (NN-DAPFAr(4)) show that 5,6-double bond of DCPD is removed with 2,3-double bond remaining. Produced poly(DCPD) with MAO cocatalyst is quite rigid and insoluble in common organic solvents but rather brittle.