Allen electronegativities

Allen GC, Warren KD (1974) The Electronic Spectra of the Hexafluoro Complexes of the Second and Third Transition Series. 19 105-165 Alonso JA, Baibas LC (1993) Hardness of Metallic Clusters. 80 229-258 Alonso JA, Baibas LC (1987) Simple Density Functional Theory of the Electronegativity and Other Related Properties of Atoms and Ions. 66 41-78 Andersson LA, Dawson JH (1991) EXAFS Spectroscopy of Heme-Containing Oxygenases and Peroxidases. 74 1-40 Antanaitis BC, see Doi K (1988) 70 1-26... 

No bands were reported by Brown et al. corresponding to charge-transfer transitions, and their absence below 50 kK. was confirmed by Allen et al. Since the lowest Laporte-allowed band for the PdCle- anion is found close to 30 kK. (24), this is as would be expected from optical electronegativity considerations. 

Observation of the list of borazine derivatives produced photochemically (Table 3) reveals that all of the reagents yielding photochemical products have an electronegative element (either 0,N,F,C1, or Br) which substitutes at the boron site. No B-C bonds have been formed photochemically, even when, as in the CH3Br and the HFA reactions, methyl or perfluoromethyl radicals are present Also, no B-C bonded compounds were formed when borazine was photolyzed with benzene, pyridine, cyclopentadiene, allene, ketene, acetylene, or acetone. 

A number of useful properties of the Group 1 elements (alkali metals) are given in Table 8. They include ionization potentials and electron affinities Pauling, Allred-Rochow and Allen electronegativities ionic, covalent and van der Waals radii v steric parameters and polarizabilities. It should be noted that the ionic radii, ri, are a linear function of the molar volumes, Vm, and the a values. If they are used as parameters, they cannot distinguish between polarizability and ionic size. 

Fig. 4.5. Allen spectroscopic electronegativity versus cation bonding strength.

Allen, L. C. (1989). Electronegativity is the average one-electron energy of the valence-shell electrons in ground-state atoms. J. Amer. Chem. Soc. Ill, 9003-14. 

Alkyl complexes, 655-657 Alkyne complexes, 662-666 Allen, L. C., 191 Allred-Rochow electronegativities, 190, 195 Ally complexes, 666-668 Alternation of electronegativities, 884-885... 

The articles by Allen cited above are also recommended as the most recent review of various aspects of electronegativity theories and for the idea that electronegativity is the third dimension of the periodic chart."... 

Allen, L. C.J.Arn. Chem. Stic. 1989. 111,9003-9014, Acc. Client. Res. IWO,23, 173-176 A Am. Chem. Stic. 1992.114,1510-1511 Can. J. Chem. 1992,70.631-635. Note that Allen s spectroscopic electronegativity, like Mulliken s. will normally be expressed in terms of electron volts, but can he converted to the Pauling scale if desired. 

More recently, in 1989, Allen developed his spectroscopic scale, xs, where he equated the electronegativity of an atom to its configuration energy (CE)... 

Fig. 1.43 Allen electronegativity values and Pauling-based values for carbon hybrids...

Fig. 1.44 Electronegativity as the third dimension of the periodic table (adapted with permission from L. C. Allen, J. Am. Chem. Soc., 1989, 111, 9003. Copyright 1989 American Chemical Society)...

TABLE 13.2 A Comparison of Pauling s and Allen s Electronegativity Values for Selected Representative Elements... 

Allen has made a strong case that his system for obtaining electronegativities is more meaningful than that created by Pauling. Allen s values are now becoming accepted by the chemical community. 

The second route to allenes is from enynes (equation 98) - > - . Variations in the placement of the electronegative group, the triple and double bonds as well as... 

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