Electronegativity Mulliken-Jaffe

Electronegativities Mulliken-Jaffe system. Recall that canonical forms that are low in energy and stable... 

Kier and Hall noticed that the quantity (S -S) jn, where n is the principal quantum number and 5 is computed with Eq. (2), correlates with the Mulliken-Jaffe electronegativities [19, 20]. This correlation suggested an application of the valence delta index to the computation of the electronic state of an atom. The index (5 -5)/n defines the Kier-Hall electronegativity KHE and it is used also to define the hydrogen E-state (HE-state) index. 

To obtain a complete picture of bonding in acid-base interactions, three separate factors must be taken into account a) the electrostatic energy of the acid-base interaction b) the covalent energy of the acid-base interaction c) the energy involved when electron transfer takes place. These results were anticipated in principle on the basis of Mulliken-Jaffe electronegativity.37... 

Mulliken-Jaffe The method of treating electronegativities that has the firmest theoretical basis is the... 

Recently Parr and Pearson6 have used the b parameter to investigate the hard and soft properties of metal ions and ligands. They have termed this the absolute hardness in comparison to the Mulliken-Jaffe a parameter which they call absolute electronegativity. They provide strong arguments for the use of the absolute hardness parameter in treating hard-soft acid-base (HSAB) interactions. 

However, we cannot exclude the s-basis set electronegativity scale just through comparison between scales since other similar discrepancies appear (even in the main groups) when the Mulliken-Jaffe and the Xa methods are compared, for instance (see the Table 4.12). In any case, the present s-basis set results may help in judging also the various criteria of validity for an electronegativity scale, see Section 4.7.2. Looking to the transition metal... 

FIGURE 4.16 The comparative representation of the atomic electronegativities of Mulliken-Jaffe (MJ), experimental (EXP), and transition state (Xa) respecting the chemical Mulliken one (4.279) with the recorded values of Table 4.12 by path integral (PI) and basis set (BS) methods (Putz, 2009b). 

FIGURE 4.17 From top to bottom, the representations of the orbital electronegativities and of the absolute chemical actions for C, N and O atoms versus the different percent contribution of s orbital (p 0%, sp 25%, sp 33%, sp 50% and s 100%) in pseudopotentials and basis set frameworks of electronic densities computation with path integral (PI), basis set (BS), and Mulliken-Jaffe (MJ) results of Table 4.13 (Putz et al., 2005,2009b). 

TABLE 5.12 Electronegativities of selected elements using the revised Pauling scale, the Mulliken-Jaffe scale, and Allen s spectroscopic configuration energies. The iatter scales have been converted to the revised Pauling scale. The Mulliken-Jaffe values are listed for the sp valence hybridization, uniess otherwise indicated. 

The absolute hardness is not to be confused with the Mulliken-Jaffe definition of electronegativity, given by Equation (14.25), where the electronegativity / is defined as the average of the IE and EA (for the valence electrons). The absolute hardness and... 

TABLE 14.11 The ionization energy (IE), electron affinity (EA), Mulliken-Jaffe electronegativity (x), and absoiute hardness (r ) for seiected Lewis acids and bases. 

Mulliken-Jaffe electronegativity x) and absolute hardness ( /) for the halide ions, defined using the frontier molecular orbital model. 

Mulliken-Jaffe s electronegativity. Mulliken and Jaffe proposed in the 1930s an electronegativity scale in which the electronegativity of a given species, M, is defined as the arithmetic mean of its electron affinity, denoted i.e., a measure of the tendency of an atom to form a negative species, and its ionization potential denoted 1, a measure of the tendency of an atom to form a positive species, both expressed in eV ... 

When investigating this question, Hinze and Jaffe [3] introduced the concept of orbital electronegativity and developed a semi-empirical method to calculate the ionization potential (ly) and electron affinity, ) of any valence state. This allowed to determine electronegativity according to Mulliken s procedure taking into account the corresponding v ence states of atoms... 

---