Pauling electronegativities

Selected Values from the Pauling Electronegativity Scale... 

IP, ionization potential [/], EA, electron affinity [7], av atom polanzabihty [2], r, van der Waals radius [3], Xp- Pauling electronegativity... 

We can use Pauling s empirical formula, which defines the Pauling electronegativity scale, for dissociation energies of a diatomic gold molecule. 

Fig. 35. (a) Correlation between the photolysis rate of halomethyl-cobalamins and the electronegativity of the alkyl ligand. (The electronegativity values are shown as the sums of the Pauling electronegatives of the atoms attached to the methyl carbon.) (b) Correlation between pKa for displacement of benzimidazole and alkyl group electronegativity for a series of halomethyl-cobalamins... 

The coupling constants increase with increasing sum of the electronegativities (E EN) of the substituents. A least square fit results in the nonlinear correlation (Pauling electronegativities)... 

Zinc, Cu and Ni have similar ionic radii and electron configurations (Table 5.6). Due to the similarity of the ionic radii of these three metals with Fe and Mg, Zn, Cu and Ni are capable of isomorphous substitution of Fe2+ and Mg2+ in the layer silicates. Due to differences in the electronegativity, however, isomorphous substitution of Cu2+ in silicates may be limited by the greater Pauling electronegativity of Cu2+ (2.0), whereas Zn2+ (1.6) and Ni2+ (1.8) are relatively more readily substituted for Fe2+ (1.8) or Mg2+ (1.3) (McBride, 1981). The three metals also readily coprecipitate with and form solid solutions in iron oxides (Lindsay, 1979 Table 5.7). 

What Pauling electronegativity is predicted for an element X if the ff-Xbond energy is 402 kj mol-1 The ff-ff bond energy is 432 kj mol-1 and the X-X bond energy is 335 kj mol-1. What would be the percent ionic character of the H-X bond If the molecular wave function is written as... 

FIGURE 1. The relationships between the methyl deviation, 5(CH3— Z), and Pauling electronegativity of the bonded Z atom in various homologous functional group series, CH3—(CH2)m—Z. See References 17b and 18... 

We have shown19 that there are separate but nearly parallel linear relationships between the methyl deviations, 6(CH3—Z), of methyl substituted species CH3—Z and the electronegativity of the atom in Z bonded to carbon for functionality in the second row of the periodic table (Z = —OH, —NH2, —CH3, —B<) and in the third row of the periodic table (Z = —Cl, —SH, —Al<). If the methyl deviations for CII3B1 and (CH3)4Ge, both containing fourth-row atoms, are now calculated and the results plotted versus the Pauling electronegativity, the two new points fall on the line established by the third-row series (Figure 1). 

Fig. 3.24 (a) Relation between the heat of formation, A H, of metal borohydride in the unit of kJ/ molBH and the Pauling electronegativity of the cation, [190]. (b) The desorption temperature, Tj, as a function of the Pauling electronegativity of the cation, Xp Inset shows the correlation between and estimatedA for the desorption reaction [173]... 

In summary, on the one hand, metal borohydrides with low Pauling electronegativities (<1.3) exhibit high decomposition temperatures. Unfortunately, at the moment there is no viable approach on the horizon by means of which high decomposition temperatures of metal borohydrides could be reduced to a reasonable level, say, 200°C. On the other hand, metal borohydrides with the Pauling electronegativities... 

The Pauling electronegativities of carbon and tellurium are, respectively, 2.5 and 2.1. This, in addition to the large volume of the tellurium atom (atomic radius 1.37, ionic radius 2.21), promotes easy polarization of Te-C bonds. The ionic character of the bonds increases in the order C(sp ) Te>C(sp ) Te>C(sp)-Te, in accordance with the electronegativity of carbon accompanying the s character (Table 1.1). 

Element Atomic number Atomic mass Electronic configuration Pauling electronegativity Ionization potential Ionic radius Atomic radius... 

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