The Stabilization of High Oxidation States

There is an interesting paradox in transition-metal chemistry which we have mentioned earlier - namely, that low and high oxidation state complexes both tend towards a covalency in the metal-ligand bonding. Low oxidation state complexes are stabilized by r-acceptor ligands which remove electron density from the electron rich metal center. High oxidation state complexes are stabilized by r-donor ligands which donate additional electron density towards the electron deficient metal centre. 

6 The d Orbitals, Covalent Character and Variable Oxidation States - A Summary 

In Fig. 9-2, we offer a schematic summary of the determinants of covalent character in transition-metal bonding. 

5 Consequences of the /-Electron Configuration upon Reaction Rates 

Thus far, we have focused upon the thermodynamic consequences of the fi-electron configuration. Many everyday observations in transition-metal chemistry have more to do with the relative rates of reactions rather than the position of a thermodynamic equilibrium. So now we consider some of the kinetic manifestations of partially filled d orbitals. 

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Seth, M., Cooke, F., Pehssier, M., Heully J.-L. and Schwerdtfeger, P. (1998) The Chemistry of the Superheavy Elements II. The Stability of High Oxidation States in Group 11 Elements. Relativistic Coupled Cluster Calculations for the Fluorides of Cu, Ag, Au and Element 111. Journal of Chemical Physics, 109, 3935—3943. 

The Stabilization of High Oxidation States of the Late 3d-Metals... 

Lattice energies may be used to understand many important chemical trends, including the characteristic oxidation states of metallic elements, the stabilization of high oxidation states by oxide and fluoride, and trends in the thermal stability of oxoanion salts such as carbonates. Stability and reactivity (B3) Solubility of ionic substances (E4)... 

Seth, M., Cooke, F., Schwerdtfeger, P., Heully, J.-L., Pelissier, M. The chemistry of the superheavy elements. II. The stability of high oxidation states in group 11 elements Relativistic coupled cluster calculations for the di-, tetra- and hexafluoro metallates of Cu, Ag, Au, and element 111. J. Chem. Phys. 109, 3935-3943 (1998)... 

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