Theoretical Analysis of Polynuclear Zinc Complexes Isolobally Related to Hydrocarbons.

Based on the isolobal analogy of ZnCp (Cp = η-CH) and ZnR (R = alkyl or aryl group) fragments with hydrogen atom and fragment [Zn(CO)] with a CH carbene, the following complexes [(ZnCp){µ-Zn(CO)}], , [(ZnPh){µ-Zn(CO)}], , [(ZnPh){µ-Zn(CO)}(ZnCp)], , [(ZnCp){µ-Zn(CO)}], , [(ZnPh){µ-Zn(CO)}], , [(ZnPh){µ-Zn(CO)}(ZnCp)], , [Zn(CO)], and [Zn(CO)], , were built. These polynuclear zinc compounds are isolobally related to simple hydrocarbons (methane, ethane, cyclopropane and cyclopentane). They have been studied by density functional theory (DFT) and quantum theory of atoms in molecules (QTAIM) to compare the nature and topology of the Zn-Zn bond with previous studies.

Effect of Basicity on the Hydrolysis of the Bi(III) Aqua Ion in Solution: An Ab Initio Molecular Dynamics Study.

Hydrolysis of the Bi(III) aqua ion under a range of solution conditions has been studied by means of ab initio molecular dynamics simulations. While the Bi(III) aqua ion is stable in pure water, there is an increasing degree of hydrolysis with the number of hydroxide anions in the medium. This is accompanied by a monotonic decrease of the total coordination number to an asymptotic value of ∼6, reached under extreme basicity conditions.

Understanding the role of the cosolvent in the zeolite template function of imidazolium-based ionic liquid.

In this work, a study for understanding the role played by [ClBmim], [BF4Bmim], [PF6Bmim], and [CH3SO3Bmim] ionic liquids (ILs) in the synthesis of zeolites is presented. The use of [ClBmim] and [CH3SO3Bmim] ILs, as reported earlier [ Chem. Eur.

Quantum-mechanical study on the aquaions and hydrolyzed species of Po(IV), Te(IV), and Bi(III) in water.

A systematic study of [M(H(2)O)(n)(OH)(m)](q+) complexes of Te(IV) and Bi(III) in solution has been undertaken by means of quantum mechanical calculations. The results have been compared with previous information obtained for the same type of Po(IV) complexes ( J. Phys.

An ab initio molecular dynamics study on the hydrolysis of the Po(IV) aquaion in water.

Po(IV) in water has been studied by means of Car-Parrinello molecular dynamics (CPMD) simulations. A new Trouiller-Martins pseudopotential for Po(IV) has been developed. This pseudopotential was tested by comparing the structure and energetics of small [Po(H(2)O)(n)(OH)(m)](4-m) clusters optimized quantum-mechanically.

General quantum-mechanical study on the hydrolysis equilibria for a tetravalent aquaion: the extreme case of the Po(IV) in water.

A systematic study of the different hydrolyzed species derived from the hydrated Po(IV) in water, [Po(H(2)O)(n)(OH)(m)]((4-m)) for 1 m 4, and 4 m + n 9, has been carried out by means of quantum mechanical computations. The effects of outer solvation shells have been included using a polarizable continuum dielectric model. For a fixed number of hydroxyl groups, the preferred hydration number for the Po(IV) can be determined in terms of Gibbs energy.

Po(IV) hydration: a quantum chemical study.

This work presents a theoretical study on the hydration of Po(IV) in solution. Three points have been addressed: (i) the level of calculation needed to properly describe the system under study, (ii) the hydration number of Po(IV), and (iii) the nature of the polonium-water bonding. The condensed medium effects have been included by means of a continuum solvation model, thus different [Po(H(2)O)(n)](4+) hydrates were embedded in a cavity surrounded by a polarizable dielectric medium.

Liquid methanol Monte Carlo simulations with a refined potential which includes polarizability, nonadditivity, and intramolecular relaxation.

Monte Carlo simulations of liquid methanol were performed using a refined ab initio derived potential which includes polarizability, nonadditivity, and intramolecular relaxation. The results present good agreement between the energetic and structural properties predicted by the model and those predicted by ab initio calculations of methanol clusters and experimental values of gas and condensed phases. The molecular level picture of methanol shows the existence of both rings and linear polymers in the methanol liquid phase.

A classical point charge model study of system size dependence of oxidation and reorganization free energies in aqueous solution.

The response of water to a change of charge of a solvated ion is, to a good approximation, linear for the type of iron-like ions frequently used as a model system in classical force field studies of electron transfer. Free energies for such systems can be directly calculated from average vertical energy gaps. Exploiting this feature, we have computed the free energy and the reorganization energy of the M2+/M3+ and M1+/M2+ oxidations in a series of model systems all containing a single Mn+ ion and an increasing number of simple point charge water molecules.

Ligand Field Effects on the Aqueous Ru(III)/Ru(II) Redox Couple from an All-Atom Density Functional Theory Perspective.

The [RuCl6](4)(-)(aq) → [RuCl6](3)(-)(aq) + e(-) and [Ru(CN)6](4)(-)(aq) → [Ru(CN)6](3)(-)(aq) + e(-) half redox reactions are investigated using density functional based ab initio molecular dynamics methods. The aim is to understand at a microscopic level how the difference in π-bonding of these ligands is reflected in the redox chemistry. To this end, we have computed the redox and reorganization free energies using a method derived from the Marcus theory of electron transfer.

Study of the stabilization energies of halide-water clusters: an application of first-principles interaction potentials based on a polarizable and flexible model.

The aim of this work is to compute the stabilization energy E(stab)(n) of [X(H(2)O)(n)](-) (X identical with F, Br, and I for n=1-60) clusters from Monte Carlo simulations using first-principles ab initio potentials. Stabilization energy of [X(H(2)O)(n)](-) clusters is defined as the difference between the vertical photodeachment energy of the cluster and the electron affinity of the isolated halide. On one hand, a study about the relation between cluster structure and the E(stab)(n) value, as well as the dependence of the latter with temperature is performed, on the other hand, a test on the reliability of our recently developed first-principles halide ion-water interaction potentials is carried out.