ON THE APPLICATION OF A MODIFIED SANDERSON FORMALISM TO ATOMIC CHARGEC-1S BINDING-ENERGY CORRELATION IN SOME AROMATIC-MOLECULES

Citation
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
Citations number
42
Categorie Soggetti
Spectroscopy
ISSN journal
03682048
Volume
85
Issue
3
Year of publication
1997
Pages
249 - 256
Database
ISI
SICI code
0368-2048(1997)85:3<249:OTAOAM>2.0.ZU;2-P
Abstract
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.