Micro solvation

Micro solvation dynamics at the passage of conical intersections observed in argon clusters of excited tetrakis(dimethylamino) ethylene... 

Solvent KIEs for MeCl + Cl in the presence of 1—4 molecules of water were examined by ab initio calculations.70 The ratio h/ d was <1 for the monohydrated system and > 1 for the dihydrated system it increased with the number of micro solvating water molecules, owing to breakage of hydrogen bonds in attaining the transition state. 

In particularly thorough examples of the traditional physical organic approach, Parker (1969) and Abraham (1974) interpreted solvent effects on Walden inversion reactions by using thermodynamic transfer functions. However, in order to explain the reaction rate decrease upon solvation from a microscopic point of view, quantum mechanical electronic structure calculations must be carried out. Micro-solvated Sn-2 reactions were initially studied in this way, with the CNDO/2 semiempirical molecular orbital (MO) method, by using the supermolecule... 

Dupuis, M., Aida M., Kawahsima Y. and Hirao K., A polarizable mixed Hamiltonian model of electronic structure for micro-solvated excited states. I. Energy and gradients formulation and application to formaldehyde.. J.ChemPhys. (2002) 117 1242—1255. 

The other study [66] is a very recent one on aqueous micro solvation of mercury halide species. The methods and level of theory employed were MP2 and DFT/B3LYP. The general trend was that oxidation of mercury halide species was seen to be favoured by the presence of water molecules. Notably the reactions (2a) and (3a)-like channel HgX - - Y together with the reaction... 

A. Fujii, T. Ebata, and N. Mikami, Direct observation of weak hydrogen bonds in micro-solvated phenol infrared spectroscopy of OH stretching vibrations of phenol-CO and -CO2 in So and Do, J. Phys. Chem. A 106, 10124-10129 (2002). 

Zhu H, Blom M, Compagnon 1, Rijs AM, Roy S, von Helden G, Schmidt B (2010) Conformations and vibrational spectra of a model tripeptide change of secondary structure upon micro-solvation. Phys Chem Chem Phys 12 3415... 

Moreover, with the exception of micro-solvation shell, quite small differences are observed for the water structure around the MOx syn- and anti-isomers. 

A partial, or micro-, solvated model is generated by adding some number of water molecules to the electrode-adsorbate interface explicitly to solvate the adsorbate. We discuss here the use of a model comprised of one or two water bilayers above the metal surface [6-12 water molecules ona3x3(lll) surface of an fee metal]. A water bilayer model with nine water molecules on a 3x3 Pt(lll) surface is shown in Figure 3.6(b). Because the bare electrode surface is covered with water molecules at an aqueous-metal interface, the adsorption of an anion is taken to occur with an adsorbed water molecule being replaced ... 

The explicit inclusion of an applied electric field at the metal aqueous interface is considered in the same manner as described in the vacuum condition. System energies as a function of applied field are given for the water bilayer and micro-solvated sulfate in Table 3.3. The potential dependent adsorption energy becomes ... 

A similar expression can be written for an oxidation reaction. The free energy of the adsorbed species may be calculated at a vacuum, micro-solvated, or fully solvated interface. Corrections to the energy difference between the two adsorbed species may be made using the dipole-field correction (Model 2a.2), and applied electric field (Model 2a.3), or the double-reference method (Model 2b. 1). 

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