CO2 Activation Within a Superalkali-Doped Fullerene
Giovanni Meloni, Andrea Giustini, Heejune Park
Abstract
With the aim of finding a suitable synthesizable superalkali species, using the B3LYP/6-31G* density functional level of theory we provide results for the interaction between the buckminsterfullerene C 60 and the superalkali Li 3 F 2 . We show that this endofullerene is stable and provides a closed environment in which the superalkali can exist and interact with CO 2 . It is worthwhile to mention that the optimized Li 3 F 2 structure inside C 60 is not the most stable C 2v isomer found for the “free” superalkali but the D 3h geometry. The binding energy at 0 K between C 60 and Li 3 F 2 (D 3h ) is computed to be 119 kJ mol −1 . Once CO 2 is introduced in the endofullerene, it is activated, and the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="minf1"><mml:mrow><mml:mover accent="true"><mml:mrow><mml:mi>O</mml:mi><mml:mi>C</mml:mi><mml:mi>O</mml:mi></mml:mrow><mml:mo stretchy="true">^</mml:mo></mml:mover></mml:mrow></mml:math> angle is bent to 132 ° . This activation does not follow the previously studied CO 2 reduction by an electron transfer process from the superalkali, but it is rather an actual reaction where a F (from Li 3 F 2 ) atom is bonded to the CO 2 . From a thermodynamic analysis, both CO 2 and the encapsulated [Li 3 F 2 ⋅CO 2 ] are destabilized in C 60 with solvation energies at 0 K of 147 and &lt; −965 kJ mol −1 , respectively.