Ionic geminals

These sense in which terms like conjugative interactions, nonbonded interactions, etc., are meant will become clear when we discuss each individual type of interaction or effect. Suffice to say that, in many instances, conjugative interactions as well as geminal interactions or bond ionicity effects contain implicitly the idea of nonbonded interactions. Thus, it should be emphasized that the labels of the basic types of interactions proposed here reflect the way in which the problem is formulated rather than different electronic principles. 

In the Hartree-Fock approximation, the GS is given by HF) = + +) and Fhf = —t + U. Let us examine the Hartree-Fock results by defining the ionic and nonionic geminals, respectively ... 

The kinetics data of the geminate ion recombination in irradiated liquid hydrocarbons obtained by the subpicosecond pulse radiolysis was analyzed by Monte Carlo simulation based on the diffusion in an electric field [77,81,82], The simulation data were convoluted by the response function and fitted to the experimental data. By transforming the time-dependent behavior of cation radicals to the distribution function of cation radical-electron distance, the time-dependent distribution was obtained. Subsequently, the relationship between the space resolution and the space distribution of ionic species was discussed. The space distribution of reactive intermediates produced by radiation is very important for advanced science and technology using ionizing radiation such as nanolithography and nanotechnology [77,82]. 

At the initial stage of reactions, the produced intermediate species such as the cation radical and the electron exist in a narrow space, the so-called spur. After the electron thermalization process, a pair of a cation radical and a thermalized electron remain in a spur. The geminate ion recombination of the cation radical and the electron occurs before these ionic species diffuse and spread uniformly in the media. Therefore the geminate ion recombination takes place in the spur. On the condition of a so-called single pair model,... 

Phenylsulfonyl)allene and geminal disubstituted dicyanoallenes react with enamines 22 giving 3-alkylidene-l-aminocyclobutanes. The alkylidenecyclobutanes equilibrate via the same zwitter-ionic intermediates.20... 

Coherent dissociation Geminate recombination Dephasing Proton transfer Electron transfer Vibrational relaxation 8arrierless reactions Bimolecular reactions Ionic reactions Solvation dynamics Friction dynamics Polarization (kerr)... 

The irradiation of all kinds of solids produces pairs of the point Frenkel defects hereafter denoted just AB-vacancies, v, and interstitial atoms, i, which usually are well correlated spatially [1-10]. In many ionic crystals these Frenkel defects are the so-called F and H centres discussed in Chapter 3. The function of the initial distribution of complementary defects - v, i pairs (called also geminate) over relative distances depends strongly not only on the particular mechanism of defect creation but also on the particular irradiation kind (e.g., X-rays or photons) [9]. Under creation of v, i pair an interstitial... 

Organoboron compound, geminal, 219 Organodiboron derivatives, 193 Organodielement halides, 79-83 Organoelement halides, 99 Os-Cl exchange, 186 Osmium boryl complexes, 179 Oxidation, ionic liquids, 278-279... 

Using the separation of the effective Hamiltonian into the unperturbed part and the perturbation, the total ionic contribution to the geminal is calculated exactly (vari-ationally). Only the bond polarity needs to be estimated perturbatively in the linear response approximation, but now the correlated ground state of the symmetric effective bond Hamiltonian is taken for evaluating the response function. In this context, it is convenient to use a dimensionless bond asymmetry parameter ... 

Geminate ion pair Ion pair, formed from a precursor that constitutes a single kinetic entity. I.e. by electron transfer or ion transfer in an encounter complex (cf collision complex) or by ionic dissociation of a single molecular entity. 

Yang J, Kondoh T, Norizawa K, Nagaishi R, Tagushi M, Takahashi K, Rat oh R, Anishchik SV, Yoshida Y, Tagawa S. (2008) Picosecond pulse radiolysis Dynamics of solvated electrons in ionic liquid and geminate ion recombination in liquid alkanes. Radiat Phys Chem 77 1233-1238. 

---