Ligand Field Stabilization Energy LFSE

In order to compare the structural options for transition metal compounds and to estimate which of them are most favorable energetically, the ligand field stabilization energy (LFSE) is a useful parameter. This is defined as the difference between the repulsion energy of the bonding electrons toward the d electrons as compared to a notional repulsion energy that would exist if the d electron distribution were spherical. 

Table 9.1 Ligand field stabilization energies (LFSE) for octahedral and tetrahedral ligand distributions...

Labile species are usually main group metal ions with the exception of Cr2+ and Cu2+, whose lability can be ascribed to Jahn-Teller effects. Transition metals of classes II and III are species with small ligand field stabilization energies, whereas the inert species have high ligand field stabilization energies (LFSE). Examples include Cr3+ (3d3) and Co3+ (3d6). Jahn-Teller effects and LFSE are discussed in Section 1.6. Table 1.9 reports rate constant values for some aqueous solvent exchange reactions.8... 

Using LFT, the change in the ligand-field stabilization energy (LFSE) for the charge disproportionation reaction (eq I) can be estimated for Mn and Co as shown in Figure 7. 

The double-hump behavior depicted in Fig. 2 is usually rationalized in terms of the ligand field stabilization energy (LFSE). The LFSE is a function of the d configuration and the magnitude... 

Some of the manifestations of the ligand field stabilization energy (LFSE) have already been described. It can be shown that producing a five-bonded transition state in a dissociative process or a seven-bonded transition state in an associative process would invariably lead to a loss of LFSE except for a few cases such as d° or d5 high-spin ions where the LFSE is zero. However, the loss of LFSE is different in a dissociative process depending on whether the five-bonded transition state is a trigonal bipyramid or a square-based pyramid (sometimes called a tetragonal pyramid). 

Ligand-field stabilization energy (LFSE) can exercise an important control on the stabilities of transition-metal complexes, particularly for... 

The energy difference between the actual distribution of electrons and that for all electrons in the uniform field levels is called the crystal field stabilization energy (CFSE). It is equal in magnitude to the ligand field stabilization energy (LFSE) described later in this chapter. 

Although we shall not be concerned with the mathematics of ligand field theory, it is important to comment upon it briefly since we shall be using ligand field stabilization energies (LFSEs) later in this chapter. 

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