Chemistry IV Reactions and Mechanisms

Reactions of coordination compounds are understood using the same fundamental concepts applied to all reactions. The chemistry of coordination compounds is distinctive because (1) the complexes have a relatively large diversity of geometries and more possibilities for rearrangement, and (2) metal atoms impose significant variability on the reactivity of their complexes. 

Reactions of coordination complexes can be divided into (1) substitution at the metal center, (2) oxidation-reduction, and (3) reactions of the ligands that do not change the attachments to the metal center. Reactions that include more elaborate rearrangements of ligand structures are described in Chapter 14 within the context of organometallic chemistry. 

The fundamental reason for our examination of reaction kinetics and mechanisms in Chapter 12 is to understand how coordination complexes can interact with other species to affect chemical change. The information gleaned from these studies allows more rational design of reactions to optimize yields and curb the formation of unwanted by-products. 

We will first review the background of reaction mechanisms, then consider the major categories of such mechanisms, and finally describe the results of mechanistic studies. 

FIGURE 12.1 Energy Profiles and Intermediate Formation, (a) No intermediate. The activation energy is the energy difference between the reactants and the transition state, (b) An intermediate is present at the small minimum at the top of the curve. The activation energy is measured at the maximum point of the curve. 

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Chapter 12 Coordination Chemistry IV Reactions and Mechanisms TABLE 12.3 Ligand Field Activation Energies... 

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