V. Patil et al., ON THE APPLICATION OF A MODIFIED SANDERSON FORMALISM TO ATOMIC CHARGEC-1S BINDING-ENERGY CORRELATION IN SOME AROMATIC-MOLECULES, Journal of electron spectroscopy and related phenomena, 85(3), 1997, pp. 249-256
The modified Sanderson formalism for calculation of atomic charge in o
rganic molecules has been shown to yield good correlation with core le
vel binding energy (BE) shifts in organic molecules where final state
relaxation effects can be neglected. Based on the concept of stability
ratios, which is similar to electronegativity, this approach has the
advantage of being intuitive in addition to being computationally non-
intensive. However, in aromatic molecules where delocalized pi electro
ns can contribute significantly to final-state relaxation energies, no
attempt has been made to study whether such a correlation is feasible
. In this communication, we seek to study the correlation between the
C 1s binding energy (BE) in some aromatic organic molecules and the at
omic charge on the carbons determined using the modified Sanderson met
hod. A linear regression curve is found to fit the data satisfactorily
with the degree of fit being better than for charges calculated by th
e MNDO quantum chemical method. There is, however, a difference in the
regression curves for aromatic molecules and molecules with carbon in
the sp(3)-hybridized state (Sastry, J. Electron Spectrosc, in press).
If the discrepancy is attributed to final-state core hole relaxation
effects, calculated relaxation energies are found to be unphysical. Th
is aspect notwithstanding, the quality of the regression found for aro
matic molecules suggests that the modified Sanderson formalism can be
applied to aromatic molecules with some care. (C) 1997 Elsevier Scienc
e B.V.