Ligand repulsion energy

The repulsion energy coefficient X can be separated into the individual ligand repulsion energy coefficients Tf for each ligand ... 

It is predicted that those atoms with the largest individual ligand repulsion energy coefficients, that is those which are the most sterically crowded, will have the longest bond lengths. Differences in repulsion energy can lead to differences in bond length of about 5%. 

White, D.P., Anthony, J.C. and Oyefeso, A.O. (1999) Computational measurement of steric effects the size of organic substituents computed by ligand repulsive energies./. Org. Chem., 64, 7707. 

Calculations of the ligand-ligand repulsion energies for 8-coordination polyhedra show that both of these polyhedra are more stable than the cube, for all values of n from 1 to 12 in a repulsion law of the type, force proportional to r ", and that the antiprism is marginally more stable than the dodecahedron. The very small difference in stability is shown by the adoption of the two configurations by chemically similar pairs of complexes such as those shown above and in Table 3.5. 

Although the sum of all potential energies was used to define the steric energy of a molecule. Brown found a very poor correlation between this quantity and kinetic or thermodynamic parameters known to be under steric control (9). Thus, Brown defined a new quantitative measure of the steric influence of a ligand, called the ligand repulsive energy, . ... 

The label has been reserved fca the Cr(CO)5 fragment. Ligand repulsive energies computed with other fragments are called R(ffagment). 

Thus far in this chapter all steric measures presented have been based on a single conformation of the ligand. In the case of ligand repulsive energies, attempts... 

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