Novel Applications of Conceptual Density Functional Theory Based Descriptors in Explaining Chemical Reactivity of Organic Reactions

Abstract

The thesis deals with novel applications of conceptual density functional theory (DFT) based reactivity descriptors to yield detailed information about chemical reaction s thermodynamics, kinetics, and mechanism. In particular, an altogether new approach has been adopted in this thesis to describe chemical reactions for a given substrate with another reactant under different conditions (in gas-phase and in solvent), formation of major and minor products, reaction mechanism including interpretation of rate-determining step, enhancement of rate and yield using these descriptors at qualitative level. Essentially, we have demonstrated how the correlation between experimental data and these reactivity descriptors can explain the kinetic aspects and the mechanism of chemical reactions. We have further generalized the adopted approach to particular type of reactions for which it is applicable. The reactivity descriptor developed by Parr et al. known as global electrophilicity index, has been considered mainly in the present thesis along with the other global and local reactivity descriptors since the majority of the reactions can be analyzed through the concept of electrophilicity/nucleophilicity of various species involved. newline In chapter 1, the brief review of literature, objectives and motivation for the present thesis are given. An overview on the theoretical developments of the conceptual density functional theory (DFT) based global and local chemical reactivity and selectivity descriptors (such as, electronegativity, chemical potential, hardness, softness, Fukui function, electrophilicity index, etc.) and the related electronic structure principles (i.e., electronegativity equalization principle, hard-soft acid-base principle, maximum hardness principle) have been presented.