Ring-opening polymerization of cyclohexene oxide by a novel dicationic palladium catalyst

The synthesis of a novel, air- and moistures table dicationic palladium (II) complex, Pd(CH3CON-(2-pyridyl)(2))(CH3CN)(2)(2+) (PF6-)(2) (1) is described. 1 crystallizes in the mononoclinic space group C2/m, a = 2391.11(4), b = 1063.34(5), c = 1137.59(6) pm, alpha = 90 degrees, beta = 105.026(2)degrees gamma = 90 degrees, Z = 4. Its use in the ring-opening polymerization (ROP) of cyclohexene oxide in comparison to the parent catalyst, dichloropalladium di(pyrid-2-yl)amide (2) was investigated. In contrast to 2, 1 shows excellent reactivity in the ROP of cyclohexene oxide, allowing a class-II living polymerization, however, it fails to polymerize propylene oxide.