Fig. 5: Prediction of threshold pressures for maximum catalytic performance.
From: Understanding low-pressure CO2 insertion chemistry in epoxide–CO2 copolymerization catalysis
a, Plot of threshold pressure for maximum catalytic performance (Pthreshold) versus polymerization rate constant, kobs, at 5 bar CO2 pressure and 50 °C. Squares represent kobs for the PO–CO2 ROCOP, and triangles for CHO–CO2 ROCOP. kobs values were determined as the average of n = 2 independent runs, with errors indicated as ± the standard error from the mean, typically falling ±10%. Data for catalyst 5 were taken from ref. 13. Crosses represent measured values of kobs,5 bar and predicted Pthreshold values for catalysts 1, 2, 5 and 6 for the CHO–CO2 ROCOP (Supplementary Table 13). b, Table showing the predicted Pthreshold and the measured catalytic performance at Pthreshold and at a pressure above it (20 bar) for catalysts 1, 2, 5 and 6. The rate data, kobs, were obtained at 50 °C, using catalyst (0.025 mol%, 2.5 mM), CHO (6 ml, 9.9 M), trans-1,2-cyclohexanediol (0.5 mol%, 49 mM). c, Structures of the catalysts 1, 2, 5 and 6 for which Pthreshold was successfully predicted. The symbol colours in the graphs correspond to the catalysts colour with their associated numbering as defined in Fig. 2.
