Sequestration of CO2 by Phosphatrane Molecules

Abstract

The stationary points for the reaction between the CO₂ and nine different phosphatranes molecules have been characterized by means of MP2 computational methods. Two minima structures have been located: a pnicogen bonded complex where one of the oxygen atoms of CO₂ acts as electron donor and an adduct that presents a covalent P-C linkage. The corresponding transition state structure linking the two minima has also been characterized. In gas phase, the pnicogen bonded complex is more stable than the corresponding adduct except in one case. In contrast, the inclusion of the solvent effect (toluene and THF), reverts the stability, being in all cases the different adducts more stable than the pnicogen bonded complexes. The electronic properties of the systems have been analysed with the Quantum Theory of Atoms in Molecules (QTAIM) and Electron Density Shift (EDS) methods.

Keywords: CO2 sequestration; molecular recognition; non-covalent interactions; phosphatranes; pnicogen bonds.