Cobalt porphyrin complex ((TPPCoX)-X-III) (TPP = 5, 10, 15, 20-Tetraphenylporphyrin; X = halide) in combination with ionic organic ammonium salt was used for the regio-specific copolymerization of propylene oxide and carbon dioxide. A turnover frequency of 188 h(-1) was achieved after 5 h, and the byproduct propylene carbonate was successfully controlled to below 1%, where the obtained poly(propylene carbonate) (PPC) showed number average molecular weight (M-n) of 48 kg/mol, head-to-tail content of 93%, and carbonate linkage of over 99%. When the polymerization time was prolonged to 24 h, PPC with Mn over 115 kg/mol and head-to-tail linkage maintaining 90% was prepared, whose glass transition temperature reached 44.5 degrees C. (c) 2008 Wiley Periodicals, Inc.