THE FUKUI FUNCTION - A KEY CONCEPT LINKING FRONTIER MOLECULAR-ORBITALTHEORY AND THE HARD-SOFT-ACID-BASE PRINCIPLE

This paper demonstrates that the Fukui function plays a central role i n the study of chemical reactivity and selectivity. Both the Frontier Molecular Obital (FMO) Theory and the Hard-Soft-Acid-Base (HSAB) princ iple are intrinsically related to the Fukui function. By using an ener gy perturbation method within the framework of density functional theo ry (DFT), we have shown that the FMO theory can be understood as a par t of the HSAB principle. The selectivity of a chemical reaction is det ermined by the nature of the reaction. Thus, for a hard reaction, the site of minimal Fukui function is preferred; for a soft reaction, the site of maximal Fukui function is preferred.