Fukui function tools

In addition we will consider the possibility to obtain reliable theoretical information on the preferred attach sites for proton and metal cations and on the potential energy surfaces (PES) that cannot be determined experimentally even with the most modern and sophisticated mass-spectrometric instruments [22,23j. Furthermore, we will propose the way to rationalize some of chemical properties by using the concepts of hardness, softness and other reactivity indices (Fukui functions) for which an exact definition exists only in the framework of DFT 1111. These last fascinating tools can contribute to increase funhemiore the DFT use going in the "core" of molecules to predict and explain basic chemical concepts. 

Abstract. The Fukui function, f r), was proposed as a tool for deducing the relative reactivity of different positions in a molecule by Parr and Yang in 1984. Herein we sketch the theory of the Fukui function, with special emphasis on its logical motivation, interpretation, qualitative characteristics, and practical computation. We conclude with some words about the Fukui function s extensions, limitations, and importance. 

One such principle is provided by the Fukui function, proposed by Parr and Yang in 1984 as a tool for understanding and predicting the relative reactivity of... 

The Fukui function successfully predicts relative site reactivities for most chemical systems. As such it provides a method for understanding and categorizing chemical reactions. More importantly, the Fukui function can be used to predict what the products of a given reaction will be. As computing the Fukui function becomes faster and easier, its predictive ability might be routinely used to winnow the list of potentially useful reagents, catalysts, etc. before performing the types of experiments or calculations necessary to fully characterize a chemical reaction. This predictive ability renders the Fukui function an important tool of the chemist. 

It is shown that Density Functional Theory offers both a conceptual and a computational tool for chemists in relating electronic structure of atoms and molecules to their properties both as isolated systems and upon interaction. The computational performance of DFT in the calculation of typical DFT quantities such as electronegativity and hardness and in the ev uation of atomic electronic affinities and molecular dipole and quadrupole momCTits is assessed. DFT concepts are discussed as such (a non finite difference evaluation of the electronic Fukui function, local softness and its use in similarity analysis of peptideisosteres and the nuclear Fukui function as a indicator of nuclear rearrangemCTits upon reaction) and in the context of principles (EEM, MHP, HSAB) for a variety of reactions involving the influence of solvent on the acidity of alcohols and the addition of HNC to dipolarophiles. 

In order to keep its practical advantages and avoid these mentioned ambiguities, one can use a well-studied mathematical tool (the topological analysis) to characterize the Fukui function [44]. This has been applied before to analyze both the... 

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