Synthesis and use of α-methoxyphenylmethylium hexachloroantimonate as a novel initiator for the polymerization of propylene oxide

α-Methoxyphenylmethylium hexachloroantimonate was prepared from α-methoxybenzyl chloride and antimony pentachloride at 0°C and isolated for the first time, and its visible and ¹H-NMR spectra were measured. This salt was used as a novel initiator for the polymerization of propylene oxide (PO) in the temperature range ?20 to 30°C with dichloromethane as solvent. PO polymerized spontaneously but a limit yield was observed. The microstructure of PO polymer is amorphous by ¹³C-NMR. The PO polymerization is thought to proceed in the conventional cationic mechanism on the basis of the polymerization behavior and the analyses of both the polymer structure and end groups attached to the PO polymer.