Table 1. Calculated Reaction Energies for Reactive CO2 Capture by the [CH(CN)2]– Anion without and with the Explicit Tetraethylphosphonium ([P2222]+) Cationa.
| reactant | product | ΔE (kJ/mol) |
|
|---|---|---|---|
| without cation | with cation | ||
| [CH(CN)2]− + CO2 | [CH(CN)2COO]− | –18.2 | –10.3 |
| [E-C(CN)2COOH]− | –39.8 | –43.3 | |
| [Z-C(CN)2COOH]− | –48.4 | –52.1 | |
| 2[CH(CN)2]− + 2CO2 | [CH(CN)2COO]22– | –23.6 | –30.6 |
| [E-C(CN)2COOH]22– | –40.0 | –53.5 | |
| [Z-C(CN)2COOH]22– | –71.4 | –90.0 | |
a
All numbers in the table are based on per mole of CO2. The energy sum of separate carbanions and CO2 molecules is set as zero.