Structure and photoelectron spectral properties of I(-)·nCO2 clusters: an ab initio study

An ab initio study on the structure, energetics and spectra of F(CO2)n−: the observation on the strong F–CO2 bond

Bulk VDE and SE values decrease from fluoride to iodide (F⁻ > Cl⁻ > Br⁻ > I⁻) in both CO₂ and H₂O.

Formation of large clusters of CO2 around anions: DFT study reveals cooperative CO2 adsorption

The cooperative O⋯C secondary interactions compensate for the diminishing effect of primary anion⋯C interactions in anionic clusters of CO₂ molecules.

An ab Initio Study on the Structure, Energetics, and Spectra of Cl-···(CO2)n Clusters

Structures, energetics, and photoelectron spectral properties of Cl^-···(CO₂)_n (n = 1-8) clusters are studied by ab initio electronic structure methods, namely, Møller-Plesset second-order perturbation theory (MP2) correlated consistent, aug-cc-pvtz basis functions. The most stable structure for each size is evaluated by using both bottom-up and top-down approaches. It is observed that CO₂ molecules approach to the chloride anion in an asymmetric way except for Cl^-···(CO₂)₈ cluster. We do observe the applicability of the simple classical electrostatic model for charge-quadrupole interactions to the solvation of the chloride anion by the solvent CO₂. Both vertical electron detachment energies and solvation energies are calculated for all the clusters at the MP2 level. We do observe an excellent agreement between theory and experiment for the vertical detachment energy, solvation energy, and gas phase detachment energy of chloride anion. It is also observed that the detachment energy of the chloride anion is increased by 4.09 eV due to the solvation effect of bulk CO₂ and it is quite small in contrast to the increase of 5.29 eV due to the solvation effect of polar solvent, water.

A theoretical study on structures, energetics, and spectra of Br-.nCO2 clusters: towards bridging the gap between micro-domain and macro-domain

Structures, energetics, and spectra of Br(-).nCO(2) (n = 1-8) clusters are studied based on ab initio electronic structure theory. The geometry of each size of clusters is evaluated by employing second-order Moller-Plesset (MP2) perturbation theory. It is observed that the solvent CO(2) molecules approach the bromide moiety from one side in an asymmetric fashion except for the Br(-).8CO(2) cluster. Simple electrostatic model for charge-quadrupole interactions is valid for the Br(-).nCO(2) clusters. Reduced variational space based energy decomposition method shows that the electrostatic interaction is the major component and polarization and charge transfer energies are the other significant components of the total interaction energy. Both adiabatic and vertical electron detachment energies and solvation energies are calculated at MP2 level of theory. We have observed an excellent agreement between theory and experiment for the vertical detachment and solvation energies. Calculated quantities based on the analytical expression which connects the finite domain to macroscopic one are found to be very good in agreement with the available experimental results. The present study reveals a 2.6 eV increase in the detachment energy of bromide anion due to the solvation effect of CO(2), which is relatively small compared to that of the corresponding 4.7 eV increase in detachment energy in water.