Absolute Electronegativities

In order to assess the contribution of polar factors to the reactivities of fluori-nated radicals, one needs a measure of their electronegativities. Absolute electronegativities (x) maybe derived if one knows both the IPs and the EAs of radicals [47], as shown below in Eq. (2). 

It is obvious that electronegativity-based aromaticity A poorly correlates with almost all traditional aromaticity scales and criteria, except with the magnetic susceptibility exaltation based aromaticity the fascinating point here is that the best correlation of A with electronegativity absolute aromaticity parallels its poorest eorrelation with ehemieal hardness... 

The nitrate ion (N03) is one of the most electronegative ions and its absolute velocity... 

Bartolotti LJ (1987) Absolute Electronegatives as Determined from Kohn-Sham Theory. 66 27-40... 

Parameter to Absolute Electronegativity. Journal of the American Chemical Society, 105, 7512-7516. 

UV/VIS spectrophotometry can be used to determine many physico-chemical characteristics of compounds and thus can provide information as to the identity of a particular compound. Although UV/VIS spectra do not enable absolute identification of an unknown, they are frequently used to confirm the identity of a substance through comparison of the measured spectrum with a reference spectrum. However, UV spectrophotometry is not highly specific, and can obviously only be applied to polymer additives which are absorbers of UV radiation, i.e. contain chromophoric groups. Both UV and IR monitor functional entities rather than the entire molecular structure. A functional group s proximity to other electropositive or electronegative structures in a molecule affects the absorbance spectrum, allowing one to infer some details of molecular structure. 

Parr RG, Pearson RG (1983) Absolute hardness companion parameter to absolute electronegativity. J Am Chem Soc 105(26) 7512-7516... 

As indicated, the magnitudes of three-bond F—F and F—H coupling constants are observed to vary as a function of the sum of the electronegativities of the other substituents that are on the two carbons in question, with the absolute values of these coupling constants... 

In a covalent single bond between unlike atoms, the electron pair forming the a bond is never shared absolutely equally between the two atoms it tends to be attracted a little more towards the more electronegative atom of the two. Thus in an alkyl chloride (20), the... 

Pearson, R. G. (1986). Absolute electronegativity and hardness correlated with molecular orbital theory. Proc. Natl. Acad. Sci. U.S.A. 83, 8440-8441. 

Pearson, R. G. Absolute electronegativity, hardness, and bond energies, Bonding Energetics in Organometallic Compounds , Ed. Marks, T. J. American Chemical Society Washington, 1990, pp. 251-262. 

R. G. Pearson, Hard and soft acids and bases—the evolution of a concept. Coord. Chem. Rev. 100, 403-425 (1990) R. G. Pearson, Absolute electronegativity and hardness. Application to inorganic chemistry. Chem. Br. 31, 444-447 (1991) R. G. Pearson, Recent advances in the HSAB concept. J. Chem. Educ. 64, 561 (1987). 

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