Table 1. ROCOP of CO2/CHO Using Catalysts 1–4/PPNCla.
| entry | catalyst | T (°C) | time (h) | conversn (%)b | CO2 (%)c | polym (%)d | TONe | TOF (h–1)f | Mn [Đ] (kg mol–1)g |
|---|---|---|---|---|---|---|---|---|---|
| 1 | 1 | 80 | 24 | 13 | >99 | >99 | 263 | 11 | 17.1 [1.04] |
| 7.6 [1.16] | |||||||||
| 2 | 1 | 100 | 16 | 17 | >99 | 80 | 342 | 21 | 7.5 [1.21] |
| 3 | 2 | 80 | 24 | 42 | >99 | >99 | 840 | 35 | 36.8 [1.05] |
| 10.7 [1.33] | |||||||||
| 4 | 2 | 100 | 16 | 65 | >99 | 65 | 845 | 81 | 37.6 [1.06] |
| 8.5 [1.56] | |||||||||
| 5 | 3 | 80 | 24 | 40 | >99 | >99 | 800 | 33 | 37.9 [1.11] |
| 16.1 [1.07] | |||||||||
| 6 | 4 | 80 | 24 | 32 | >99 | >99 | 640 | 27 | 21.6 [1.02] |
| 9.7 [1.04] | |||||||||
| 7 | [(Boxdipy)TiIVCl]h | 60 | 12 | 45 | >99 | >99 | 900 | 76 | 13.0 [1.27] |
| 8 | [(NHC)TiIVCl2]i | 80 | 24 | 53 | >99 | >99 | 1325 | 55 | 8.3 [1.53] |
| 9 | [(Salalen)TiIVCl]j | 70 | 10 | 44 | 98 | 98 | 220 | 22 | 4.2 [1.11] |
Reaction conditions unless specified otherwise: catalyst (0.05 mol %), cocatalyst (0.05 mol %), CHO (8 mL, 9.9 M), 40 bar of CO2.
Expressed as a percentage of CHO conversion vs the theoretical maximum (100%), determined from the 1H NMR spectrum by comparison of the relative integrals of the resonances assigned to the carbonate (4.65 ppm for PCHC and 4.00 ppm for trans cyclic carbonate) and ether (3.45 ppm) linkages against CHO (3.00 ppm).
Expressed as a percentage of CO2 uptake vs the theoretical maximum (100%), determined by comparison of the relative integrals of the 1H NMR resonances due to carbonate (4.65 ppm for the polymer and 4.00 ppm for the trans cyclic carbonate) and ether (3.45 ppm) linkages.
Expressed as a percentage of polymer formation vs the theoretical maximum (100%), determined by comparison of the relative integrals of the 1H NMR resonances due to the polymer (4.65 ppm) and trans cyclic carbonate (4.00 ppm).
Turnover number (TON) = number of moles of cyclohexene oxide consumed/number of moles of catalyst.
Turnover frequency (TOF) = TON/time (h).
Determined by GPC, in THF, calibrated using narrow-Mn polystyrene standards.
Catalyst (0.01 mmol), cocatalyst (0.01 mmol), CHO (20 mmol).27
Catalyst (0.008 mmol), cocatalyst (0.008 mmol), CHO (20 mmol), 10 bar of CO2.26
Catalyst (0.2 mol %), cocatalyst (0.2 mol %), CHO (9.9 M), 40 bar of CO2.29