Propylene oxide (PO) binding and ring-opening reaction with the bifunctional CO
2/epoxide copolymerization catalyst, based on the Co(III)-salcy complex including two quaternary ammonium salts with
n-butyl substituents (N
+-chains) were investigated by Density Functional Theory (DFT) calculations and compared with
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Propylene oxide (PO) binding and ring-opening reaction with the bifunctional CO
2/epoxide copolymerization catalyst, based on the Co(III)-salcy complex including two quaternary ammonium salts with
n-butyl substituents (N
+-chains) were investigated by Density Functional Theory (DFT) calculations and compared with the model systems without the N
+-chains. The importance of the different possible stereoisomers and the stereoselectivity of these processes for (
S)- and (
R)-enantiomers of PO were considered. To explore the conformational space for the real catalyst, a complex approach, developed previously was applied. The calculations for the model systems directly demonstrate that PO-ring opening proceeds preferentially in
trans catalysts’ configuration and no participation of
cis-β isomers is viable; nucleophilic attack at the methylene-carbon atom is preferred over that at methine-carbon atom. For the real bifunctional catalyst, with the (
S,
S)-configuration of cyclohexane, the results indicate a preference of (
R)-PO ring-opening over (
S)-PO ring-opening (ca. 6:5). Concerning stereoisomers resulting from the orientation of N
+-chains in the real catalyst, different groups of structures participate in the ring-opening reaction for (
R)-PO, and different for (
S)-PO. The high population of nonreactive complexes of (
R)-PO may be the key factor responsible for decreasing the activity of the analyzed catalyst in the epoxide ring-opening reaction.
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