Charge-dipole repulsion

By exploiting electrostatic field effects (unfavourable through-space charge-dipole repulsion) to increase the nucleophilic susceptibility of cyclohexanones, more efficient catalysts (16) and (17) for epoxidafion through in situ dioxirane formation have been designed. ... 

When the reaction is well-established as a radical one it is still possible to find explanations of polar substituent effects, usually in terms of ion-radical intermediates, dipole-dipole repulsion, solvation, or charge-transfer structures like those postulated for -complexes.488 Reac-... 

The potential of mean force due to the solvent structure around the reactants and equilibrium electrolyte screening can also be included (Chap. 2). Chapter 9, Sect. 4 details the theory of (dynamic) hydro-dynamic repulsion and its application to dilute electrolyte solutions. Not only can coulomb interactions be considered, but also the multipolar interactions, charge-dipole and charge-induced dipole, but these are reserved until Chap. 6—8, and in Chaps. 6 and 7 the problems of germinate radical or ion pair recombination (of species formed by photolysis or high-energy radiolysis) are considered. 

Charge Dipole Quadrupole London Electron repulsion... 

In chloroacetic acid the interaction of the dipole of the Cl—C bond with the dipole of the carboxylic acid group is destabilizing because the positive end of one dipole is closer to the positive end of the other. The interaction of these like charges is repulsive and increases the energy of the molecule... 

Exchange repulsion Dispersion Charge transfer Charge-charge Dipole-dipole Polarization of i by j... 

Before refining these values, and adding dipole-dipole repulsions and induced dipoles, the top H20 was examined to see if it would influence the most probable bottom position. Because DP multipole point-charge calculations are tedious, some simplifying assumptions were made. The H30+ lone pair points directly at the O in the top H20, whose lone pairs point downwards in either a symmetrical or Verwey position. However, the repulsions between the 6 H30+ bond electrons and the 4 top H20 lone pair electrons appear to steer the... 

The initial disclosure of a [6 + 4] cycloaddition between tropone (1) and a 1,3-dipole involved diphe-nylnitrilimine as depicted in Scheme In this instance the [6 + 4] pathway competed rather poorly with various alternative [4 + 2] pathways and only a small quantity of the adduct in which the dipole added across the 2- and 7-positions of (1) was recovered. The three [4 + 2] adducts (45)-(d7) that were isolated from the reaction mixture presumably arose from a base-catdyzed hydrogen shift that occurred subsequent to the initial cycloaddition. Efforts to account for the divergent behavior of dienes and 1,3-dipolar species in their reactions with tropone have included invoking a dipole repulsion between the large positive charge located on the central atom of the 1,3-dipole and the partial positive charge on tropone, which must come into close proximity in the transition state of a concerted [6 + 4] cycloaddition. A ca-... 

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