Molecular geometries and energetics of metal-containing systems using an improved ASED-MO model: a systematic test to group 1 and 2 metal containing systems in the gas phase

Dissolution of a base (RbOH) by water clusters

Density functional and ab intio calculations are employed in order to understand the base dissociation of rubidium hydroxide by water molecules. The hydrated structures, stabilities, thermodynamic quantities, dissociation energies, infrared spectra, and electronic properties of RbOH(H2O)(n = 0-5) are investigated. With the successive addition of water molecules to RbOH, the Rb-OH bond lengthens significantly from 2.45 angstroms for n = 0 to 3.06 angstroms for n = 5. It is interesting to note that four water molecules are needed for the stable dissociation of RbOH (as an almost dissociate conformation) and five water molecules are needed for the complete dissociation without any Rb-OH stretch mode, in contrast to the same group base of CsOH which requires only three water molecules for an almost dissociate conformation and four water molecules for the complete dissociation.

Aqua dissociation nature of cesium hydroxide

To understand the mechanism of aqueous base dissociation chemistry, the ionic dissociation of cesium-hydroxide in water clusters is examined using density functional theory and ab initio calculations. In this study, we report hydrated structures, stabilities, thermodynamic quantities, dissociation energies, infrared spectra, and electronic properties of CsOH(H(2)O)(n=0-4). With the addition of water molecules, the Cs-OH bond lengthened significantly from 2.46 A for n=1 to 3.08 A for n=4, which causes redshift in Cs-O stretching frequency. It is found that three water molecules are needed for the dissociation of Cs-OH, in contrast to the case of strong acid dissociation which requires at least four water molecules. However, the dissociation for n=3 could be considered as incomplete because a very weak CS em leader OH stretch mode is still present, while that for n=4 is complete since the Cs em leader OH mode no longer exists. This study can be related with hydration chemistry of cations and anions, and extended into the intra- and intercharge-transfer phenomena.