The Time Evolution of the Electronegativity - Modern Trends in Chemistry and Chemical Engineering - page 46

an experimental evaluation of the chemical potential of the electrons of the exchanged
cation and of the host site in zeolites. This step leads to an evaluation of the funda-
mental parameters, such as the effective hardness and electronegativity of the sites of
zeolites. Such an approach gives an evaluation of the heterogeneity of the alumino-
silicate surface and is applied to an exchanged hydrogen mordenite containing various
amounts of substituted lithium ions or sodium ions.
Schaeffera et al. [83] have applied the empirical relationship between electronega-
tivity and effective work function to a diverse set of multi-element electrode materials
on hafnium dioxide (HfO 2 ) gate dielectrics. To accommodate the multi-element nature
of metal gate electrodes, the group electronegativity of the metal was calculated from
the geometric mean of electronegativity with respect to the volume stoichiometry of
the constituent elements. Their fi nding suggested that the group electronegativity con-
cept is also extended to work function engineering via dielectric capping materials.
The electronegativity trends provide insight into the relative charge neutrality levels
of candidate dielectric capping materials and their subsequent impact on the metal ef-
fective work function.
Baeten and Geerlings [84] used the electronegativity equalization principle to
study the charge distributions in enzymes.
Ramsden [85] studied the infl uence of electronegativity on the triangular three-
centre two-electron bonds. Recently, Reddy et al. [86] showed the correlation between
the optical electronegativity and the refractive index of ternary chalcopyrites, semi-
conductors, insulators, oxides, and alkali halides.
Douillard et al. [87] obtained the solid surface tension of ideal crystals of talc and
chlorite. From this result, it is possible, using thermodynamic models, to calculate
the heat of immersion in water of these solids and to compare with experimental data
obtained for well-known samples. Their study confi rmed that the differences between
surfaces of talc and chlorite and confi rming that a route of calculation of surface ten-
sion using electronegativity equalization is very simple and correct.
Kwon et al. [88] opined that the electronegativity and chemical hardness are the
two helpful concepts for understanding oxide nanochemistry.
Makino [89] pointed out that the band gap, heat of formation and structural map-
ping for sp-bonded binary compounds can be interpreted on the basis of bond orbital
model and orbital electronegativity.
A relationship between dehydroxylation temperature and electronegativity was
suggested by Ray et al. [90].
The relationship between the electronegativity and the charge-injection barrier at
organic/metal interfaces was suggested by Tang, Lee, Lee, and Xu [91].
Portier, Campet, Etourneau, Shastry, and Tanguy [92] studied the exclusive role of
electronegativity in the materials design. Nowaday, the electronegativity equalization
methodology, EEM, [93-96] is frequently used to calculate the charge distribution
and reactivity index, for example, local softness and hardness [97, 98], condensed
Fukui function [99], electrophilicity index [99, 100] of molecules. Chemical Reactiv-
ity Theory (CRT) contains reactivity indices defi ned as fi rst and second derivatives of