Quantifying cooperative intermolecular interactions for improved carbon dioxide capture materials

Abstract

We have optimized the geometry and calculated interaction energies for over 100 different complexes of CO(2) with various combinations of electron accepting (Lewis acid) and electron donating (Lewis base) molecules. We have used the recently developed explicitly correlated coupled cluster singles doubles and perturbative triples [CCSD(T)-F12] methods and the associated VXZ-F12 (where X = D,T,Q) basis sets. We observe only modest changes in the geometric parameters of CO(2) upon complexation, which suggests that the geometry of CO(2) adsorbed in a nanoporous material should be similar to that of CO(2) in gas phase. When CO(2) forms a complex with two Lewis acids via the two electron rich terminal oxygen atoms, the interaction energy is less than twice what would be expected for the same complex involving a single Lewis acid. We consider a series of complexes that exhibit simultaneous CO(2)-Lewis acid and CO(2)-Lewis base intermolecular interactions, with total interaction energies spanning 14.1-105.9 kJ mol(-1). For these cooperative complexes, we find that the total interaction energy is greater than the sum of the interaction energies of the constituent complexes. Furthermore, the intermolecular distances of the cooperative complexes are contracted as compared to the constituent complexes. We suggest that metal-organic-framework or similar nanoporous materials could be designed with adsorption sites specifically tailored for CO(2) to allow cooperative intermolecular interactions, facilitating enhanced CO(2) adsorption.

Theoretical insights on electron donor–acceptor interactions involving carbon dioxide

“…Theoretical studies on model systems have been carried out to analyze the interactions of CO 2 with carbonyl compounds. [13][14][15][16][17][18][19][20][21][22][23][24][25] Former studies did confirm the existence of EDA complexes in which, as expected from simple chemical considerations, CO 2 play the role of the electron acceptor (i.e., it behaves as a Lewis acid). Recent work, however, has revealed the existence of other unconventional EDA structures.…”

The effect of large amplitude motions on the vibrational intensities in hydrogen bonded complexes

“…We did not correct the electronic energy of the complex to account for the basis set superposition error, as these corrections have been shown to give results further from the complete basis set limit when the explicitly correlated coupled cluster methods are used. 55,56 …”

Computational Studies of CO2 Activation via Photochemical Reactions with Reduced Sulfur Compounds

“…These distances are comparable to those between CO 2 carbon atom and CH 2 S or C 4 H 4 S calculated by de Lange et al . 42 using explicitly correlated CCSD(T)-F12a/VDZ-F12 methods. The reaction then proceeds through TS1H-S0 to generate carbiothioic O,S -acid ( INT1H-S0 ) via simultaneous formation of the C-S and O-H bonds.…”