molecular weight and polydispersity index of the obtained polymer were measured by using gpc propylene oxide 1162 g 20 0 mol in which the complex compound 2 0 224 g which is an amount calculated according to a monomer catalyst ratio was dissolved and injected to 3 l of an autoclave reactor through a cannula the complex compound 2 prepared according to the preparing example 2 was used as the complex compound carbon dioxide was input to the reactor at a pressure of 17 bars and the mixture was stirred while increasing a temperature of the reactor in a circulation water bath of which a temperature is previously set to 70 u00b0 c after 30 minutes the time point when a pressure of the carbon dioxide starts to fall was recorded and reaction is performed for 2 hours from the time point then the reaction was terminated by degassing of carbon dioxide 830 g of propylene oxide was further added into the obtained viscous solution to lower viscosity of the solution and then was passed through silica gel 50 g merck company 0 040 to 0 063 mm particle size 230 to 400 mesh pads thereby obtaining a colorless solution a monomer was removed by vacuum to obtain 348 g of white solid the obtained polymer had a weight average molecular weight mw of 316 000 and a polydispersity index pdi.