Copolymerisation at 1 eq LM AM : 1000 eq. CHO, 4 bar CO2, T = 100°C ; reaction stopped after 24h or at viscosity limit when stirring ceased. b Turnover number (TON), number of moles of CHO consumed per mole of catalyst. c Turnover frequency (TOF) determined from initial rates analysis by H NMR aliquot monitoring (typically 5 -30 % conversion) as TON/time. d Relative integrals, in the normalised 1 H NMR spectrum of tertiary CH resonances due to polymer versus c5c; e Relative integrals, in the normalised 1 H NMR spectrum of tertiary CH resonances due to carbonate versus ether links. e Determined by GPC (gel permeation chromatography) measurements conducted in THF, using narrow MW polystyrene standards to calibrate the instrument. # T = 120°C. g Copolymerisation at 1 eq LM AM : 1000 eq. CHO: 2000 eq. CS2, T = 60°C; b Turnover number (TON), number of moles of CHO/CHS coupled to heterocarbonates per mole of catalyst. h Turnover frequency (TOF) determined from rate analysis by 1 H NMR aliquot monitoring (linear region following the initiation period, typically between 10-40%) as TON/time. i Relative integrals, in the normalised 1 H NMR spectrum (CDCl3, 25°C, 400 MHz), of tertiary CH resonances due to polymeric relative to cyclic heterocarbonates; e Relative integrals, in the normalised 1 H NMR spectrum of tertiary CH resonances due to OSS versus other heterocarbonate links. $ T = 100°C.