Table 1.
Comparison of experimental data with DFT results for calculated CO2 adsorption mechanisms in e-2-OH–Mg2(dobpdc). Mechanism A yields the most stable CO2-inserted structure and the best correlation with experimental data. Chemical shift values are reported in ppm. For the 15N shifts, the first value corresponds to CO2-inserted amine nitrogen and the second value to free amine nitrogen.
| Experiment | Mechanism A | Mechanism B | Mechanism C | Mechanism D | Mechanism E | |
|---|---|---|---|---|---|---|
| E (eV) | - | −1050.919 | −1050.545 | −1050.234 | −1105.249 | −1049.916 |
| EB (kJ/mol) | −81(4) | −78 | −66 | −57 | −57 | −47 |
| a (Å) | 21.255(1) | 21.299 | 21.856 | 21.818 | 19.618 | 20.828 |
| c (Å) | 6.875(4) | 7.053 | 7.077 | 7.034 | 6.851 | 7.095 |
| δ 15N | 90(2), 41(2) | 102.4, 38.7 | 101.4, 40.4 | 101.7, 35.9 | 46.2, 33.0 | 118.2, 56.3 |
| δ 13C (C=O) | 158.5(1) | 158.5 | 158.6 | 161.7 | 158.5 | 153.7 |