Table 1 Data for propene oxide (PO)/CO2 ROCOP using the Co(III)M(I/II) catalysts, where PPC is poly(propene carbonate) and PC is propene carbonate

From: Understanding catalytic synergy in dinuclear polymerization catalysts for sustainable polymers

Entry

Catalyst

Time/h

Productivity TONa

Activity TOF/h−1b

Rate coefficient kobs/×10−3 s−1c

Selectivity CO2/%d

Selectivity PPC/%e

PPC Mn [Đ]/g mol−1f

1

Co(III)Ca(II)

22

194 ± 10

5 ± 1

0.36 ± 0.02

93

38 ± 4

700 [1.17]

2

Co(III)Sr(II)

23

889 ± 44

23 ± 2

1.79 ± 0.14

97

50 ± 5

2100 [1.07]

3

Co(III)Ba(II)

21

856 ± 43

30 ± 2

2.36 ± 0.17

97

61 ± 6

2500 [1.11]

450

Co(III)Na(I)

5

600 ± 30

104 ± 8

7.52 ± 0.60

>99

79 ± 2

2300 [1.08]

550

Co(III)K(I)

4

1360 ± 68

528 ± 42

38.20 ± 3.06

>99

98 ± 2

5900 [1.10]

650

Co(III)Rb(I)

23

1240 ± 62

88 ± 7

6.37 ± 0.51

>99

91 ± 3

6500 [1.07]

750

Co(III)Cs(I)

23

1080 ± 54

88 ± 7

6.34 ± 0.51

>99

84 ± 3

5600 [1.08]

  1. Reaction conditions: catalyst (0.025 mol%, 3.6 mM), PO (5 mL, 14.3 M), 1,2-cyclohexane diol (0.5 mol%, 71 mM), 20 bar CO2, 50 °C.
  2. aTurnover number (TON) = moles PO consumed/moles catalyst. PO conversion determined from 1H NMR spectra integrals for PPC (4.92 ppm), PC (4.77 ppm) and PPO (3.46-3.64 ppm), using mesitylene as an internal standard (0.05 mol%, 36 mM).
  3. bTurnover frequency (TOF) are determined from 5 to 20% conversions, in all cases (Supplementary Tables 1 and 2, Supplementary Eq. (1)).
  4. cCalculated from linear ln([PO]t/[PO]0) vs. time plots (Supplementary Figs. 28 and 30).
  5. dSelectivity for CO2 conversion, determined from PO conversion to PPC + PC/overall PO conversion (using NMR integrals).
  6. eSelectivity for PPC formation, determined as PO conversion to PPC/overall PO conversion (using 1H NMR spectroscopy integrals).
  7. fDetermined by GPC, in THF, at 30 °C, using narrow MW polystyrene calibrants.